Lil Red - Duramax 6600/Allison Conversion/Swap & OBS/NBS Dash Conversion

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Note: Don't miss out! This forum thread contains quite a few images. For example, just this introductory post alone contains 7 images. Send a message (http://www.thedieselpageforums.com/tdpforum/sendmessage.php) to me if you're having trouble seeing these images. If you're not already registered here at The Diesel Page Forums, please do. It's free. Register Now! (https://www.thedieselpageforums.com/tdpforum/register.php) You may need to register to see everything - or post here in this thread. I urge you to do both! Did I mention it's free? And, we don't sell or use your info for any purpose other than to help you use this bulletin board forum or answer your questions.


https://www.youtube.com/watch?v=--9bY1T3XoQ

Lil Red - Duramax Diesel Power Project

Rocket science is a whole lot more entertaining when you actually get to drive one! Yes, you can swap a Duramax 6600 and Allison 1000 into a 1988-98 GM 2/4 wheel drive pickup truck, whether 1/2 ton, 3/4 ton or 1 ton. And yes, you can also install the D/A into a 1988-98 2-door/4-door full size SUV (Tahoe, Yukon or Suburban). And yes, you can also install a Duramax 6600 and Allison 1000 into a 1973-1987 GM Square-body pickup truck/SUV. We'll show you how...

Duramax swaps - How well do they run and perform after 20 years? What is it like to drive? How long does it take when swapping a Chevy K1500's stock gas V8 for a 6.6L Duramax diesel and an Allison transmission? Many questions... You'll find the answers to many of these questions here in this forum blog, but I recommend first watching the video linked above, then continue reading. We put you in the driver's seat and then under the hood to get a better picture of what a Duramax swap is really like. ;)

This topic thread also includes a discussion about a new body style (NBS) 1999-2007 full-size GM truck dash swap for the old body style (OBS) 1988-1998 full-size trucks and SUVs. The new dash is not required to produce a running and driving Duramax Conversion/Swap, though I do recommend modifying your existing dash to accept the instrument panel gauge cluster that matches the model year of your Duramax engine. It's not all that difficult, and having the instrument panel gauges will enhance your overall Duramax swap. I cover portions of the dash installation here in this topic thread, but more information is included in the helpful Guide book we offer concerning Duramax/Allison swaps (see my signature here).

Lil Red - the Duramax/Allison conversion project truck shown here was first driven in April 2004 - and it became the very first privately owned Duramax/Allison conversion in a GM vehicle. The Diesel Page literally wrote the book on Duramax 6600/Allison conversions (http://www.thedieselpage.com/duramaxconversions.htm), and we designed the Duramax Conversion Motor Mounts (http://www.thedieselpage.com/conversionmounts.htm) that allow for a bolt-in engine swap.

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The primary mission for this Duramax Diesel Power Project was to determine the feasibility of using the Duramax 6600 and Allison 1000 automatic transmission in a range of conversion projects, including the GM full-size trucks and SUV's from 1967 onward (with slight modifications - depending on model year). This Lil Red project shown here was the beginning of all that. The above photo was taken in 2002 just after receiving the brand new Duramax 6600 crate engine directly from GM Powertrain, along with the Allison 1000 transmission and NV-263 transfer case. Updating the exterior of the truck began soon after.

In addition to the K1500 truck featured here, we also completed a 1987 Chevy C30 Square Body Duramax (https://www.thedieselpage.com/features/ClarkDMConversion.htm) here in TheDieselPage.com. That 1987 Chevy C30 diesel swap is another of many conversion projects we've been a part of.

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A 4" exhaust system, 4" polished stainless exhaust tip and Bilstein HD shocks were installed after the body work and paint had been completed. A custom exhaust system was chosen because we needed a 4" tailpipe without pre-welded hangers to work for this rather unique application. There is no muffler or catalytic converter installed, which means the truck sounds a little more like a hot-rod. The 2001 LB7 48-state emissions regulations did not require EGR, a catalytic converter or any other exhaust after-treatment - one huge plus for the 2001 LB7. The addition of a set of CalTracs traction bars help control axle-wrap during a launch. Kennedydiesel.com was helpful in working with me on some of these items.

Shown here is a set of silver-finished factory Chevy SS 6-lug 20" x 9" aluminum wheels. The matching Goodyear Eagle tires in 275/55R20 were an excellent choice, being almost 32" in diameter and more than 11" wide.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7110&d=1687287428

The original 10-bolt ½-ton rear axle was replaced with a GM six-lug 9-1/2" 14-bolt semi-floating rear axle that had been removed from a low mileage 1997 GM 1500. This rear axle was rebuilt by Randy's Ring & Pinion in Everett Washington with a new Eaton Posi-traction differential, new 3.42 ring & pinion and all new bearings and seals. An all new rear driveshaft was manufactured incorporating a 1350 series rear U-joint to match the rear differential pinion yoke and a new 1410 series U-joint & yoke/slip-joint at the front to match the Allison/NVG-263 output shaft. There has not been any detectable vibration or any other unusual behavior while using two different U-joints in this rear driveshaft. The 4WD front driveshaft was similarly manufactured using the appropriate yoke/U-joint at each end. This combination has been run at the 1/4-mile track at up to a 130-mph (in 4WD) without any sort of problem, even with more than 600 horsepower and 1200 lb-ft of torque.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7107&d=1687287166

I urge all those who embark on their own swap/conversion to work toward producing a factory "look". This will increase the value of a converted vehicle by as much as $20,000. For years now, late model 2500 series Suburbans that have a factory looking and performing Duramax/Allison conversion were being sold for at least $20,000 above the Kelly Blue Book vehicle pricing guide, simply because of the clean install of a D/A and the rarity of that combo. There was a time when people would follow D/A Suburban owners into parking lots, rest areas and fuel stations wanting to learn more about the owner's Duramax 6600 powered Suburban and their wish to buy it on the spot. And... you'd be surprised at how many individuals began businesses converting Suburbans as a result of what we've done and documented here in The Diesel Page.

This truck has appeared in a number of magazine, including the January 2007 issue of Diesel World magazine, the May 2006 issue of Diesel Power magazine and in three separate issues of Truck Trend magazine. More info about magazine coverage can be found below.

TDP - Jim Bigley

https://www.thedieselpage.com/DMCONVsm.jpg
The Duramax Conversion Guide (http://www.thedieselpage.com/duramaxconversions.htm) - This new second edition includes glossy full-color photo-quality front and back covers, a completely updated and revised interior that includes 62 glossy pages (17 B/W + 45 full color pages) filled with updated photos and graphics, along with even more information that will not only help you succeed, but will inspire you to complete your project.This professionally written and bound volume illustrates what you'll need to know when installing a Duramax 6600 diesel engine and Allison automatic transmission into a 1988-98 classic OBS (Old Body Style, like that shown here) C/K GM pickup truck or Suburban, plus boats and even a Duramax/Allison conversion in the 1980s Square Body trucks.

3/14/2023 - Keep reading! This forum thread includes videos and blog entries over time about Lil Red and its Duramax conversion. If nothing else, this shows how well the truck continues to run and perform since its completion, and it shows just how much fun Lil Red is to drive and how people we meet along the way respond to it. Check back now and then to catch up, or subscribe to this thread so you'll be notified via email when a new post has been added (using the "Thread Tools" link above the first post in this thread). In the meantime, if you have a diesel event scheduled for this year somewhere in the northwest, let me know. Lil Red and I might just come to see you!
Jim

Did this forum tread or YouTube video help you with your conversion/swap? Want to share this thread with others or help us get the word out about Duramax swaps? It's easy! Simply link to us in your own YouTube video, or post the link(s) shown here in a forum post, email message or social media site. Thank you!

thedieselpageforums.com/tdpforum/showthread.php?35210 (http://thedieselpageforums.com/tdpforum/showthread.php?35210)
https://www.youtube.com/watch?v=--9bY1T3XoQ

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Was in town on Tuesday (11-3-2020) to take a few photos of the brand new 2021 Duramax Diesel pickups. The Chevy dealership had just received their very first 2021 model year trucks... due to covid-19 delays this year, so I made arrangements with the sales manager a couple of weeks ago to drop in for a few photos when they arrived.

It was a really-really nice day here (especially for November 3), so I thought I'd drive Lil Red (https://www.thedieselpage.com/duramaxconversions.htm) to the dealership. Not many of their staff had seen Lil Red before, so it was a fun time with show-n-tell? :)

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Jim

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After driving the truck for about a month without a problem since the Duramax head gasket replacement, we decided to take Lil Red on a 300 mile overnight road trip this past Mon/Tue. It was a great trip, and there was no oil use, no coolant loss and best of all - no abnormal pressure buildup in the cooling system. :o

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This photo was taken on I-90 about 60 miles east of Missoula Montana, headed west/home. The speed limit on I-90 here is 80-mph. The 3.42 gearing and 275/55R20 tires make for fairly tall gearing. The truck loves it. Once off the Interstate, we crossed the continental divide on US-12 coming/going. Truck stays in OD with ~8-10 psi boost and ~1000 degrees EGT at 60-70 mph while climbing this 6% grade (McDonald Pass - corners determine speed). So far so good!

By the way... The above photo shows a filler piece above the steering column that I made from fiberglass, and which had been covered with vinyl imitation leather then color dyed to match the dash. This purely cosmetic filler piece was needed to adapt the round 1989 steering column to the somewhat rectangular opening in the dash where the column passes through. This is just one of the steps that you can avoid if you use the steering column removed from the same donor truck that provided the Duramax/Allison for your conversion.


https://www.youtube.com/watch?v=4-2pPGzVQ8o

Some time back, power eventually reached a max of 632-hp and 1200 lb-ft of torque on the chassis dyno while this truck was being actively campaigned. This was accomplished by using a combination of Kennedy programming, nitrous, 3.42 gearing, and an ATS Allison Extreme transmission. The above video shows that dyno run, though I can't help wondering whether those numbers might have been higher without the wheel-slip heard in the video.

Edit: The Kennedy 600+hp ECM race programming was replaced recently with a new Kennedy program (https://www.kennedydiesel.com) that includes both a stock power/fuel economy setting plus a +100 horsepower switchable setting. This was a part of a civility plan for this truck. While this truck will undoubtedly appear at select diesel events in the near future, its now mostly just a driver - to be enjoyed for what it is. So, the new ~stock programming allows the performance Allison to shift with near stock manners. Plus, it's a lot more pleasant to drive, yet it retains the muscle (when selected) that can surprise folks. Also, John corrected the speedometer for the 3.42 differential gearing and tire size as part of his programming for me - thanks John.

This engine is also running a Banks "Big Head" wastegate actuator (https://www.bankspower.com/i-1103-bighead-actuator-bighead-wastegate-actuator-kit-2001-2004-chevy-6-6l-for-2001-2004-chevy-gmc-2500-3500-6-6l-duramax.html) (shown below), which has a larger diaphragm than the stock actuator, and it includes an adjustable control rod - to control spring pre-load (thus boost pressure). Current rod adjustment produces a max of 25-psi boost pressure during a brief full pedal run - still goes like a bat even with stock power. Boost pressure quickly rises to its 25-psi max and stays there as long as your foot is in it. The truck delivered 22.13-mpg on the last fill-up (250.1 miles), which was a good part of this trip. Great fuel economy, considering the speed... I'd like to do a serious fuel economy run some day to discover what this 3.42 geared 5,000-lb truck is actually capable of when driven slower... I just need more willpower... ;)

The following image shows what Lil Red's Duramax 6600 looked like midway through an August 2021 head gasket replacement. Why were the head gaskets replaced? Answer: The engine experienced a nitrous incident at the 1/4-mile track some years earlier, which resulted in our replacing both head gaskets in late summer 2021 - though just one head gasket was affected. There's a video farther down in this thread that shows the exact moment when the "incident" occurred at the race track.

In short, too much nitrous too soon during the launch caused the fire to go out (nitrous spray is really-really cold), which set the engine up for a backfire once the nitrous had been switched off just a moment later. Apparently, the cylinders and exhaust system were filled with a combination of super fine fuel mist and oxygen-rich nitrous oxide which produced a backfire when the nitrous (extreme cold) was switched off and the engine began to run again. Note to self...

Upon tear-down, I found that 2 head bolts near cylinder 8 (rear cylinder on the driver's side) were slightly easier to remove than the other remaining head bolts on that bank, and that cylinder #8's LB7 injector cup showed signs of combustion leakage. Though the head gasket looked normal at cyl 8, I suspect the loss of clamping load and a small combustion pressure leakage at the #8 injector cup are what caused the cooling system over-pressure problem that developed soon after the nitrous incident described here. New head gaskets and a complete re-seal for all 8 injector cups have solved the problem. At the time this was posted it had been about 2 years and 5,000 miles since the head gasket service, and all appears to be good now! Such a relief.

It's amazing how much room there is to work on the engine, once the inner wheel-wells, all of the top-side engine stuff and the cylinder heads have been removed. This head gasket replacement project did provide the incentive to complete a Duramax Service Guide (https://www.thedieselpage.com/duramaxdieselserviceguide.htm), which contains complete coverage for this project and several other service procedures.

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Read more about Lil Red's Duramax Head Gasket Replacement HERE (https://www.thedieselpageforums.com/tdpforum/showthread.php?46717-Duramax-Head-Gasket-Replacement&p=331989#post331989). If you're not already registered here at The Diesel Page Forums, please do. It's free. Register Now! (https://www.thedieselpageforums.com/tdpforum/register.php) You may need to register before opening the head gasket replacement link - or post here in this thread. I urge you to do both!

Want to share this thread with others or help us get the word out about Duramax conversions? Copy the following link and paste it into another forum, email or social media site:
thedieselpageforums.com/tdpforum/showthread.php?35210 (http://thedieselpageforums.com/tdpforum/showthread.php?35210)

Jim

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As mentioned earlier, I've embarked on a civility program for Lil Red. The first step was to add a foam rubber block (5 x 5 x 24") to the back of the cowl injection hood scoop - on the inside. I theorized that a lot of engine noise was coming through the screened back of the scoop and into the cabin air inlet in the factory windshield cowl. The foam block was painted black on the visible side (visible through the windshield), so it looks like a foam air filter. That block of foam cut the noise a noticeable amount.

Next, I added a couple smaller foam blocks (each 5 x 5 x 5") that were squeezed into the area between the scoop and the underneath hood framework - near the center and close to the hood latch, to dampen resonant noise. That helped too. The hood now sounds like a normal hood when shut. I plan to add a full-size under-hood pad in the near future, to complete the hood sound abatement portion.

On the "to-do" list is a muffler. Right now, the truck is running straight piped. I'm looking for a muffler that produces a mild throaty rumble without any droning. Since I'll be driving this truck more as a fun daily driver, I want the exhaust note to be a little more civilized.

Beyond that, I'll be installing a rubber bed mat, to help with the echo chamber. It already has a fiberglass bed cover, but not much else in the way of sound deadening...

Let me know if you have any other ideas...

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I've been asked a few times these past few months about the new body style (NBS - 1999-2007 model year) dash I installed in Lil Red (1989 Chevy K1500).

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They asked whether the newer dash was too wide for the OBS (Old Body Style) cab interior, they asked about the HVAC (heating-venting-air conditioning) package used in my truck, and they asked about the electrical harnesses I used.

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The newer dash is wider than the original, but it fits if the door panels are modified to be as thin as possible. The top photo shows the modified 1989 door panel. Basically, the door panel is only about 1/8" thick where it fits against the new dash. I cut that section out of the original door panel and plastic welded in a piece of 1/8" ABS flat sheet to replace it. Then, the new ABS piece, once shaped to fit exactly, was covered in vinyl imitation leather. The final touch was using an automotive interior spray color dye to get the door panels to color-match the new dash. Once completed, the ends of the dash and the door panels "just" touch when the doors are closed. The above photo shows just how much of the original door panel had been removed.

The Heating/Venting/Air Conditioning (HVAC) package beneath the dash and the dash-mounted controller I'm using are the original 1989 units. However, if doing all this again, I'd be tempted to install a new HVAC package that matched the model year of the new dash. This way, the ducting could be easier to complete and the dash HVAC controller would be plug-n-play with both the HVAC package and the new wiring harness borrowed from the Duramax/Allison donor truck.

Speaking of electrical harnesses... I recommend using the GM factory Duramax donor truck's electrical system harnesses along with a reprogrammed factory ECM (Kennedydiesel.com and others can reprogram your factory ECM to correct for tire size and final gearing, as well as remove the factory security key lock code, if you wish - though I recommend keeping it if you can). With the exception of Lil Red's lighting system (head/tail/courtesy, etc) the remainder of the truck's wiring was swapped out for the new. This actually made the conversion easier and simpler - though you have to be committed once the original wiring system has been stripped out...

Beginning with the complete OE Duramax donor's wiring harnesses and various control modules allow you to incorporate any of the luxury and safety features into your build that are found in the newer trucks. These optional features don't have to be used/incorporated, but they are possible when using factory parts. You can pick and choose. For example, the airbag system could be transferred to your earlier truck. The 4-wheel ABS system could be transferred. Then there's the security system, audio system, climate control, even OnStar and any other feature that was found in your Duramax donor truck. In talking to (or through email) hundreds of conversion project owners, these factory offered features have been incorporated in part or in whole in some number of the trucks that have been converted through the years. The various aftermarket harnesses/ECMs are more expensive and they don't provide for any extras. Plus... if your conversion maintains stock functionality, any GM dealer or diesel service tech can help you with trouble codes or routine troubleshooting - now and into the future. This makes your truck more valuable if you ever decide to sell it.

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There's no going back... :eek: This is a very early photo showing how Lil Red's interior looked after the original dash and most of the wiring had been removed. The process was a little scary at this point, which helps to explain why it took time to make the decision...

The indecision about whether to strip out the original wiring (and swap the dash) cost me nearly a year, because at that point in time (late 2002) no one outside of GM had converted an earlier GM truck to D/A power. Seemed like a big-big risk at the time, given that this truck was such a peach to begin with, and here I was stripping out some very important parts that would make going back nearly impossible. Now, I know it's not a big risk...

Once I fully committed to moving forward, serious effort began in late 2003 and the truck first became drive-able in early April 2004 - some 4 months later. A short list of what was necessary to get to this point was motor mount design (https://www.thedieselpage.com/conversionmounts.htm) and fabrication, the dash conversion, intercooler fabrication/completion, a working air conditioning system, custom GM Corporate 9-1/2" 14-bolt 6-lug rear axle with a new Eaton posi-traction rear differential (plus new bearings, seals and ring/pinion gears), rear disc brake conversion using new 2003 model year factory GM parts, fully functioning push-button 4WD system (push-button control panel & transfer case control module), installing the new factory wiring harnesses for the NP263HD transfer case made for the Allison 1000 and Duramax engine control, new custom front/rear driveshafts, fuel tank/lines modifications, designing/implementing the layout for all of the under-hood components, completing the new bodywork/paint, installing an all new interior - including leather bucket seats/console and from new carpet/pad to a new headliner. There were a host of other additions that are likely not necessary for your project... Sounds like a lot, but it all came together in less than 4 months - when spending as few as 1 to a several hours/day working through the list as the design, photography and assembly of this brand new first-ever Duramax/Allison conversion came together.

All in all, I actually enjoyed the process, and my enthusiasm grew the closer to the finish line I became. ;) In hindsight though, I know that having the Conversion Guide would have cut the time spent to complete the conversion in half - if I'd had it to begin with. Solutions for all of the challenging parts of the conversion that I wrestled with are all included in the Duramax Diesel Conversion Guide. And of course, all of the nuts and bolts of the conversion process are also included in the guide, showing how I did it. Plus, personal help is just a phone call or email away.

All that said, I ask that those planning a conversion to consider retaining their project truck's original dash and HVAC package, and just modify the truck's original instrument gauge panel surround to accept the newer instrument panel gauge cluster from the Duramax donor - and install the modified Duramax donor's steering column (you'll need to reposition the firewall mounting bracket on that column). This simplifies the total conversion. A typical car audio shop should be able to help you create a new gauge panel surround that adapts your current dash to accept the new Duramax gauge cluster - if you need help doing that part - this is what they do for custom speaker installations, etc.

I found that installing the new dash doubled the time it took to complete the conversion in my truck. You have to be committed and you need to accurately assess your skill level if you decide to swap the dash. If you really want the newer style dash, I suggest waiting till after the D/A conversion has been completed and you've been driving the truck for a while.

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However, in all of the car shows and diesel events I've attended with this truck, I will say that I'm surprised that the newer style dash usually draws more attention/comments than does the clean OE appearance of the Duramax under the hood. Not sure what to make of that...

The dash install and most other items shown here are discussed in more detail in the Duramax Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm), and a bit more info can be found farther on in this thread.

>>> Nearly all of those who began with our Guide and mounts were able to complete their own conversion project without outside help. However, if anyone were to hit a snag in their project, I ask that they call or send me an email detailing the problem. There is a solution for every problem. Email/phone consultation is free. I've been through the process enough times to know how to help you. While it hasn't been necessary yet, I've offered a couple of conversion builders one last confidence boost before they began their own project... "bring your truck to me if necessary, and I'll help you get it running." - Jim

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Here's another interior photo from the archive - taken sometime in early 2004 - showing the interior from a different angle - before the A-pillar gauge pod and Grant steering wheel had been installed.

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I just finished the installation of a 2" receiver hitch in Lil Red. This is a "Draw-Tite Max-E-Loader Trailer Hitch Receiver - Custom Fit - Class III - 2" Item #41524". Though it says "custom", it was a production hitch that I bought from Amazon in 2018... Just got it installed...

This receiver hitch is rated for a 1,000-lb tongue weight and a 10,000-lb gross trailer weight when using a weight-distributing hitch. Without a weight-distributing hitch, the rating drops to 600-lbs/6,000-lbs. More than enough for this 1500 series chassis.

To get the hitch installed square, centered and correctly located front to back, I clamped the hitch onto the frame rails in the approximate location it needed to be using C-clamps (snug, but not too tight), then used a rubber mallet to tap the hitch into the perfect position. Then, I marked the frame for the new holes before removing the hitch from the truck and drilling the new holes. Using clamps allowed me to do the trial fitting and final mounting by myself and without drama.

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Shown here is a device (a clamp pointed to in photo) I bought from Harbor Freight that was designed to reduce the rattle/slop for anything slid into the 2" receiver. There's always a bit of clearance designed into these 2" receiver hitches, so ball hitches or whatever ... slide in easily. A rattle-stop is necessary to keep the bumper-ette tight (shown in the next image).

I also needed to relocate the exhaust tailpipe hanger due to interference with the hitch mount. The above photo was taken just before the exhaust hanger was relocated.

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Aside from the practical, i.e. towing trailers, a big reason for installing a receiver hitch was to provide some protection to the rear of the truck in case of a bump from the car behind at a stoplight or something similar. Shown here is a relatively inexpensive bumper-ette that would help. There are many other options available online that offer more strength and protection, but.. we'll see what develops. This one is pretty lightweight.

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This was a more or less custom installation because I wanted the hitch to be tucked in as tight as possible - to make it less noticeable. In a typical stock installation where the rear bumper is retained, there would be room for the spare tire, but not here due to the roll pan requiring the hitch be mounted a bit farther forward. This required drilling new holes... though I don't think this hitch could be installed without drilling some or most of the holes anyway.

The engineers at Draw-Tite were especially helpful in answering questions about an off-the-shelf hitch fitting this unique situation. Though it was designed for an unmodified truck (1988-98 body style), this is a great hitch that fits the roll-pan very well.

The only negative... the hitch shown here arrived from Amazon with some chips in the finish (the hitch is heavy and the packaging could have been better). Amazon generally does an amazing job with shipping, so I'll cut them a little slack. I touched up the chipped areas using POR-15. It's all good. I'm happy with it. Now, I just need to get the trailer wiring/connector installed along with a brake controller.

As of 3/18/2022, this receiver hitch was available at: https://www.etrailer.com/p-41524.html?hhyear=1989&hhmake=Chevrolet&hhmodel=C%2FK+Series+Pickup with free shipping for $218. Amazon was out of stock when this was posted.

Jim

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Here's an image of the Husky Liners floor mats installed in Lil Red. I bought these a few months ago, and just got them installed. I love them. I've had a set in my 2001 GMC for more than 20 years, and they haven't deteriorated at all. They are the best mats I know of to help keep the carpet clean in our Montana winters - mud, snow and winter road de-icer are rough on carpet. I used to stress about either myself or passengers tracking in stuff, but these mats make it OK. The mats keep the water, mud and dirt corralled before it can run off onto the carpet.

My first experience with these mats was when John Kennedy drove to Ohio for our 2001 TDP Rendezvous. He had these in his truck. I wasn't sure what I thought about them at that time. But, after discovering that there wasn't anything on the market that would do a better job, I bought a set for my 2001 GMC - front and rear. Great choice! I still have them, and they still look/perform as good as new. That's why I wanted a set for Lil Red and for Sarah's Blazer.

The mats are form-fit for each truck make/model. The ones shown here were made for the 1988-98 GMT-400 body style GM trucks and SUVs. They are easy to remove from the vehicle, they clean up easily with just a light scrub using soap and water, and they stay put because of all of the pointy nubs anchoring into the carpet.

The front mats cost about $75 using Amazon Prime. Not many products I like, or would buy again, after 20 years... I do/did these!
https://www.amazon.com/s?k=Husky+Liners+-+31102+Front+Floor+Liners+Fits+92-94+Blazer%2C+88-99+C1500%2FK1500+Extended+Grey+Husky+Liners+-+31102+Front+Floor+Liners+Fits+92-94+Blazer%2C+88-99+C1500%2FK1500+Extended+Grey&crid=47UN9FCP2MPH&sprefix=husky+liners+-+31102+front+floor+liners+fits+92-94+blazer%2C+88-99+c1500%2Fk1500+extended+grey+husky+liners+-+31102+front+floor+liners+fits+92-94+blazer%2C+88-99+c1500%2Fk1500+extended+grey+%2Caps%2C313&ref=nb_sb_noss

And incidentally... you can see in this photo where I relocated the truck's original 1989 hood latch release, located on the bottom rim of the dash. This has worked out just fine. It's easy to operate and yet is out of the way. And, the pictured parking brake release and parking brake system function just like they do on a new truck - warning lights, chimes and all.

Beneath the cab of the truck, I just needed to fabricate a connection between the original 1989 parking brake cable and the new (at the time) GM factory 2003 model year 1500 series rear disc brake E-brake cables/parts. The E-brake uses small shoes inside the rear rotors similar to the rear disc brake parts found on the 2500 series trucks. The rear disc brake conversion on this truck used all factory 2003 model year GM rear disc brake parts, with the exception of a custom adapter to bolt the caliper brackets and other components onto the 1997 model year axle. The rear disc brakes have been great. Going with OEM parts was less expensive than an aftermarket kit at the time, and it'll be easier sourcing any replacement/repair parts I might need in the future. I did a story on this at the time that had lots of photos and part numbers. Let me know if you need more info. - Jim

[JohnC]

Too funny! I was checking their Amazon ad to see if I could figure out where they came from (Good news, made in USA). the TV was on, and when I looked up there was a WeatherTech ad on... (I bought a WeatherTech liner for the back of the GLS last fall after the dog barfed in the back...)

[More Power]

Too funny! I was checking their Amazon ad to see if I could figure out where they came from (Good news, made in USA). the TV was on, and when I looked up there was a WeatherTech ad on... (I bought a WeatherTech liner for the back of the GLS last fall after the dog barfed in the back...)

I bought a set of WeatherTech mats for our 2016 Malibu. The anxiety from winter muck and nice carpet is a thing with me... Living in MT doesn't help...

[More Power]

I finally got around to installing the Husky Liners mud flaps for the front of Lil Red.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6581&d=1656616563

These are part number: 56221 listed as for the "1988-98 GM Truck/Suburban, Tahoe, Yukon - Mud Guard". An online search for "Husky Liner 56221 mud guard" will provide a range of vendors who carry these mud guards. Otherwise, here's a link to their corporate web site.

https://www.huskyliners.com/product-detail/56221/front-or-rear-mud-guards

I like the look, and these exact mud flaps are designed to work perfectly on trucks that have the factory fender flairs.

I put a dab of silicone caulking on each screw hole before using the supplied screws. That should help to prevent any rusting or paint chipping where the mounting screws pass through the steel fenders. I'm hoping they keep most of the rocks off the rocker panels. They make a matching set for the rear too, but... The installation of the new side steps should help with keeping the rocks off the side of the truck as well. Although... automotive accessory shops sell self-adhesive clear vinyl armor that is used to help prevent rock chip damage to vehicles. This can be applied to the lower body panels and leading edge of the hood to help prevent chips. I'm considering using the armor instead of the side steps I already have... We'll see...

Jim

[More Power]

I needed to be at a conference in early July, a ways from home here in Montana, so I took the opportunity to drive Lil Red. It was mostly all on the Interstate, with a total of 840 miles combined over a couple of days. Driving speed was mostly 80-85 with A/C. And, there were quite a few hills - up and down. So... 840 miles total, used 38 gallons of diesel @ 22-mpg. Highest price paid for diesel #2 was $6.04 at an I-90 truck stop 30-40 miles west of Bozeman, MT. Truck did great.

The Interstate rest stops were fun that last day. Seems there are always car/truck guys and gals no matter where you go. Just wish I'd taken a photo while we were there at one of the rest stops. Lil Red drew a small crowd of people. Then, within miles of leaving the rest stop, I saw in my rear view mirror that a lifted Dodge diesel truck was slowly gaining on us... We were doing 85 by then. Once they were alongside, a woman stuck her hands out the partially open passenger side window as they slowly-slowly passed - while making heart signs... My wife said it was for the truck... not me. ;)

[DieselDavy]

Jim,
I'm impressed with these MPG figures Jim. What kind of MPGs does your daughter's Tahoe get?
d

[a5150nut]

Saw an upfitted fancy Hummer today here in Knoxville with Duramax Diesel {Large Letters} decal in back window. Wasn't able to catch up with him.

[More Power]

Jim,
I'm impressed with these MPG figures Jim. What kind of MPGs does your daughter's Tahoe get?
d

Dave,
The great fuel economy is due to a few things... First, the truck weighs some 2500-lbs less than my 2500HD Crew Cab Duramax/Allison. Lil-Red's gained a little since it was first put together, but it's still less than about 5,200-lbs or so. Second, it's fairly aerodynamic for a pickup truck, rides lower than a 2500/3500, it has a front air dam, tonneau cover, 3.42 gearing and 32" tall tires (~2000-rpm at 80-mph). Third, it's an LB7 without any sort of emissions control (not necessary for this engine in this truck). My 2001 GMC D/A didn't come from GM with any factory emissions control hardware (EGR) or exhaust system cat/DPF either - the good old days...

Hard to tell for sure what the fuel economy is for Sarah's 6.5. We haven't driven it far enough, in a fuel economy setting to know. But, the one tank I did check it was 16-17 if I remember correctly, which was mostly local driving. For comparison, Lil Red gets about 19-mpg during local driving, so I suspect the 6.5 Blazer would get about 20 on the Interstate. The Blazer has 3.73 gearing and the 4L80-E has a .75 OD ratio. With the 265-75R16 tires it has, this'll produce ~2380-rpm at 80-mph, just to compare it to Lil Red. My experience with the 6.5 seems to show that 65-mph is a better fuel economy speed - or about 2000-rpm.

[More Power]

Saw an upfitted fancy Hummer today here in Knoxville with Duramax Diesel {Large Letters} decal in back window. Wasn't able to catch up with him.

There was a company in the midwest called "Lynch Hummer" back in 2002 that had converted a few H1 Hummers to Duramax/Allison. I spoke with the owner as I was preparing for the Lil Red project at that time. He was a nice guy, but not too willing to share details. I don't blame him - he had a considerable investment in what he knew. In the end, for an unspecified amount, he agreed to complete the electrical portion of my conversion if I trailered the truck to him. Luckily, I didn't need his help. ;) But, it was reassuring to have a backup just in case.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7538&d=1708721249

In 2006, I got to see the very last H1 Hummer (factory equipped with the Duramax/Allison) roll off the AM General assembly line in Mishawaka, Indiana when I was there to do a story for Diesel World magazine. The one shown here was that Hummer. It was a shiny desert sand color and had all of the options that were available. I was told that it had been ordered for the daughter or wife of one of the company principles. I don't remember how many Duramax powered H1 Hummers were eventually produced by AMG, but it was sad to see the end of production for such a unique vehicle. :(

[More Power]

I've been driving Lil Red more this summer than in years past. It's been great.

Here's a shot of Flathead Lake, here in western Montana. This is one of the largest freshwater lakes in the country at 7-15 miles wide and 28 miles long - its deepest point is 370 feet. The lake was formed as a result of a terminus of a large glacier during the last Ice Age. Luckily, we've had a little global warming since then. This shot shows the width of the lake. While involved in a research project for the University of Montana in the early 1980's, I was part of a team that took sediment core samples (some up to ~30' long) all over the lake bottom.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7088&d=1687285711

My daughter and I had driven the 150 miles to Kalispell in part to pick up some of the famous Flathead Lake cherries (they also have a Chick-fil-A ;)) that were in season. We stopped at a road-side fruit stand on the way home, where we met a local husband and wife (and Duramax owner). They noticed the Duramax emblems on Lil Red as they were driving by, so they pulled in to check it out, saying they couldn't believe this truck had a Duramax 6600 in it... So, I popped the hood, then I opened the driver's side door so they could see the interior... Was fun. :o

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7087&d=1687285711

Not far from there was a small town called Polson. Here, you'll find an eclectic museum that has quite an assortment of stuff, even including a Vought (LTV) A7 Corsair. This particular plane once belonged to the US Air Force; very similar to the A7's I worked on while serving in the US Navy. My position within the Navy was "Aviation Fire Control" technician. "Fire Control" here refers to weapons, RADAR and navigation systems (advanced electronic systems). It's hard to believe that a civilian could acquire one of these airplanes. This one was a little beat up from getting it to the museum.

Nuf of that... Lil Red produced just over 23-mpg on that Flathead Lake trip - about 400 miles in total - mostly all two-lane highway - 70ish mph (more stops, traffic and corners). Was a very fun day!

The next weekend we traveled south on Highway US-93 then east/northeast on Highway US-43 and into an area called "The Big Hole", a high elevation area of forest and mountains, that had experienced a fire a year or two earlier.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7091&d=1687285945

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7086&d=1687285711

Still a nice place to visit. It's not all burned. And, there's a national center nearby that honors the native people and their history.

Not long after the above photo was taken we continued on our journey to Butte Montana. We traveled a nice 2-lane highway that, apparently, was in the middle of a grasshopper invasion... This was still morning, so many of them had moved onto the highway to warm up...

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7085&d=1687285711

Luckily, most of them didn't get too far above the highway when they saw us coming. Otherwise, the grille would have suffered more - most didn't get above the bumper. They all washed off just fine.

The truck runs great! The coolant level stabilized a couple thousand miles ago, and hasn't required any adjustment. The engine doesn't use any oil and it remains clean (amber colored) since it was serviced about 3K ago when both head gaskets were replaced. The truck produced 22.5-mpg during this Butte Montana trip - also about 400 miles in total - about half/half 2-lane and Interstate. It's more fun on the Interstate! Jim

[DieselDavy]

Great trips (and stories of your service).
Thanks for the stories and thanks for your service Jim!
Dave

[More Power]

Great trips (and stories of your service).
Thanks for the stories and thanks for your service Jim!
Dave

Thank you for replying.

It's been amazing to me that I've had this truck since 2002 - began driving it with the D/A in April 2004. The truck doesn't seem any older to me now than it did in 2004. New trucks always begin looking older sooner. Also, keeping Lil Red garaged whenever it's not being driven helps prevent the paint and rubber parts from aging. Since it was more than 11 years old (minimum age of the vehicle for permanent plates in Montana) when I first registered it (in April 2004), I haven't paid a dime for vehicle registration since then - it has permanent plates. Insurance is also cheaper due to its age, and no vehicle I've owned gets more positive attention from other motorists than Lil Red. I've only ever been stopped once by a cop while driving it - I think it was because he wanted a closer look - I was doing the speed limit at the time, minding my own business. ;) I was stopped because Montana requires a plate at both ends of the vehicle. I didn't have one on the front bumper at the time. Do now... We had a good conversation none the less...

Here's what the truck looked like when I bought it in 2002.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7258&d=1691432935

One of the first questions people ask when they see Lil Red for the first time is "What year truck is it?" This truck is a 1989 Chevrolet Silverado (4x4 K1500) standard cab Sport-Side. It was originally equipped with a tired 350TBI and TH700R4. It was a runner/driver when I bought it in 2002 for $4500. The truck was 13 years old at the time, but I could see past the dated factory trim and faded paint. Standard cab Chevy Sportside pickups were rare then and even more rare now.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7259&d=1691434329

The prior owner had recently retired from the Atlanta Fire Department and moved to Montana. I was told that this truck was for sale, so I gave the owner a call. At that point in time it had never been driven on Montana winter roads or endured the effects of road de-icer. It was far from perfect, but the truck became a good starting point for my Duramax conversion project. The original owner knew what I planned to do with it. He thought it sounded like a cool project.

Jim

Want to share this thread with others or help us get the word out about Duramax conversions? Copy the following link and paste it into another forum, email or social media site:
thedieselpageforums.com/tdpforum/showthread.php?35210 (http://thedieselpageforums.com/tdpforum/showthread.php?35210)

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7097&d=1687286015

It's been a bit smokey here in western Montana during early September. Hopefully the cooler weather and the little rain we had yesterday will help.

This photo was taken Monday morning (September 12, 2022) just after sunrise - leaving home in the dark about an hour earlier. I was on I-90 just east of the Garrison Junction exit (175) in this photo (about 70 miles east of Missoula MT), moving along at about 85-mph - on my way to a conference in Bozeman MT. This was a 500 mile round-trip day. The truck produced just under 21-mpg on the outbound leg that morning - probably because I pushed a little harder... Coming home later that afternoon produced a little better fuel economy of 22.8-mpg.

Though I usually stop for fuel at some point, Lil Red could make this entire trip (~500 miles) on one 26 gallon tank of fuel. This truck has about a 575 mile range at 85-mph if running the fuel tank from brimming to vapors. That could be stretched out to about 650 miles per tank if I could somehow keep the speed below 70-mph - assuming the truck would produce 25-mpg at 70-mph... it has produced an Interstate fuel economy of 25-mpg once before... :)

This round-trip included Pipestone Pass, where I-90 crosses the continental divide near Butte, MT. This pass includes miles-long 6% uphill climbs from both directions. Corners here determine the speed, but there is certainly no lack of power. ;)

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7100&d=1687286015

We had about 6 inches of snowfall the past couple of days, and I hadn't moved the snow blower out of the garage yet... So, I had to first move Lil Red to get to the snow blower that was against the far wall of the garage... Was a bright beautiful day, so I thought I'd get a photo.

Before driving Lil Red to where you see it here, I first had to make sure the 4WD was working... Would have been "inconvenient" if the truck had gotten stuck and 4WD wouldn't engage... ;) The only other time the 4WD had been used prior to this was at the 1/4-mile track some years ago. Fortunately, the 4WD system worked just fine today.

Since I've been asked before, I thought I'd take this opportunity to talk about the 4WD system used in this 1989 Chevy K1500... The HD 263 push-button transfer case I used is the same one the first-gen factory Duramax/Allison powered trucks used. To allow the transfer case and front axle to work together in this truck I simply wired it in the same as the newer trucks. I studied the electrical wiring diagrams at the time this truck came together, and discovered that the older and newer trucks both used similar technology and methodology - it's just that the electrical connectors were different at the axle. As mentioned in an earlier post here in this thread, for Lil Red's Duramax/Allison conversion I used the factory engine/transmission and front axle wiring harnesses made for a 2001-2004 4WD Duramax/Allison powered 2500HD truck. I also use the factory push-button panel on the new dash. A few simple weather-sealed solder splices (original 1989 front axle harness connectors spliced onto the new 2001-2004 front axle harness) allow the original 1989 front axle and 4x4 actuator to function normally with the new push-button NVG-263 transfer case. It was all a simple plug-n-play operation once the harness connectors at the axle end had been transferred. This turned out to be one of the simpler parts of the conversion.

The truck never slipped a wheel while moving it back into the garage after this photo was taken. Since this truck has never seen winter road de-icer, it won't be driven on the highway now till spring. :( Edit- 5/24/2023 - Given the 2022/23 winter we had, becoming an Arizona snow bird doesn't sound too bad right about now... ;)

[JoeyD]

Glad to see you still have this truck after all this time.

[More Power]

Glad to see you still have this truck after all this time.

Glad to see you still check in once in a while! You've been part of this forum since 2000... since the beginning!

I made the decision some years ago that I would keep the truck, for a variety of reasons, including comments like yours. I appreciate it. :)

[More Power]

Photos from late 2003/early 2004 - There's always been an interest in the dash conversion that Lil Red received. I talked to a GMT-400 (OBS - Old Body Style, 1988-98 full-size 1500-3500) owner a couple of weeks ago who had purchased our Duramax Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm) primarily for the dash conversion info it contained. He was using an LS gas engine for his conversion, not a Duramax. One of the things he mentioned was that other than our Guide, he could not locate any help for a dash conversion. As a consequence, we talked about the dash conversion a good while during that phone call. These photos help to illustrate a portion of the dash install that he had questions about.

The following two images illustrate how I attached the steel upper dash support brackets to the upper cowl of the firewall. I don't remember exactly, but I seem to recall that there were 4-6 attach points across the width of the dash. This is just one of those attach points.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6960&d=1681231259

I made a pair of "L" brackets to attach the shortened steel dash bracket to the cowl, and I used blue thread locker on all of the associated hardware. So far, none of the screws have worked loose - since early 2004 and about 14k miles - though the angle tabs could be tacked in using a MIG welder if you're concerned about them working loose. A pair of "L" brackets at each location made it possible to use a nut-driver (or long extension + socket/ratchet) from the rear during the final install.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=6959&d=1681231259

As mentioned earlier, the dash conversion usually gets more attention than does the clean OE install of the Duramax at truck/diesel events and the few car shows I've attended with this truck. Maybe they thought that this truck came with the Duramax from the factory, and believed that just the dash was new. Just a theory... ;)

[More Power]

Was a nice day here in Montana (we've had an unusually cool and snowy spring so far), so I jumped in the truck and rolled it back out of the garage. This was the first time the truck's been out of the garage since the snow pic day in November 2022 shown earlier.

I keep the batteries charged during the winter using a trickle charger, so it cranked and started as well as though I'd started it the day before. The Duramax has always started fast even after sitting all winter without being started, some 5-6 months... every spring since 2005 - though it is on its second set of maintenance-free batteries in 20 years. I had topped off the fuel tank with summer #2 diesel fuel just prior to parking it last fall. Since this truck has the original steel fuel tank, keeping the tank full of diesel fuel over the winter helps to keep the inside of the tank in good shape. I also use Power Service fuel treatment with every tank of fuel, if that helps...

There were too many other projects going on yesterday to drive it any distance, but I did take the time to lube the door hinges, hood hinges and the hood latch mechanism. I use motorcycle chain lube for this (spray can with small ID applicator tube). The lubricant is diluted with solvent, which allows it to penetrate and then evaporate quickly, leaving a tacky super lube behind that won't run. Though I try to not overdo it during the application, I finish the process by wiping off any excess with a clean shop towel and maybe a little alcohol.

I'll be changing the engine oil in the next week or two. It's been about 4,000 miles and 18 months since the last oil/filter change. The current oil is still very clean looking, but this will be the second change since the head gasket replacement project in September of 2021... At present, I'm using Shell 15W-40 petroleum diesel-rated engine oil (white jugs) and ACDelco PF-2232 oil filters. The inside of the engine looked pristine during the head gasket replacement project, so it appears the oil choice and service intervals are doing the job.

[More Power]

Here are a couple of photos showing what the basic differences were between the two instrument panels and dashes.


https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7096&d=1687285945

The above is a comparison showing the differences between the two instrument gauge panels. Overall width was similar, but height was more of a consideration. I believe the original dash could have been made to work with the new instrument panel using a custom fiberglass gauge panel surround and a little creativity. Ultimately, what made the final push for the dash swap was both appearance and functionality - this truck would attend a few car shows in the near term as well as a number of diesel events for the next few years. And... in for a penny, in for a pound... ;)

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7095&d=1687285945

Another shot of the dash assemblies. Lots of measurements had already been taken at this point, as well as many in/out trial fits. The perspective in this photo doesn't show that the dash width was a concern.

Incidentally, the new dash didn't come with an airbag on the passenger side. They're expensive; so I cut a 1/4" thick plywood panel the right size, then covered it with foam followed by vinyl imitation leather, and then used a spray dye to color-match the panel to the rest of the dash. Once attached using hidden hardware, the panel does a good job simulating the factory airbag. I'm happy.

Post here, or use the "Contact" link in my signature if you have any questions or need more information.
Jim

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7090&d=1687285711

A friend and I drove Lil Red to a popular local lake on Saturday. We found the lake to be at full pool and quite crowded. This photo was taken just 30 yards from the only boat ramp on the lake, and it was tough to get a photo without other people in it. This was a scenic spot for a pic, even though it was sloped down rather sharply. This outing was just a 110 mile day in total, but still a great time to be out. Montana is beautiful in June... The reward for surviving too many months of cold and snow... ;)

My friend and I talked about hot-rods and classic cars for most of this drive. He owns both a '55 and '57 Chevy that he is currently restoring. I even volunteered to help with the sheet metal repairs... hoping to spur him on... What was I thinking? :eek:
Jim

[DieselDavy]

Sure looks good for it's age Jim!
I enjoy all of these posts you've been making. I'm sure I'm not the only one. Keep 'em coming!
Dave

[More Power]

Sure looks good for it's age Jim!
I enjoy all of these posts you've been making. I'm sure I'm not the only one. Keep 'em coming!
Dave

Thanks Dave.

Daughter Sarah and I drove Lil Red into Missoula (medium sized town about 25 miles north via a 4-lane highway) a few days ago. A guy in a new all black F150 sport truck came up behind us in the passing lane (4 lane highway). We were in the right side driving lane doing the speed limit. I could see that the F150 was gaining on us, so I slowly increased the speed to keep pace. Can't resist... Then he really got after it, and went by us at about 100-mph. I had already backed off to the speed limit (70), but caught up to him a couple of miles further on at a stoplight. As luck would have it, we wound up side by side, with us on his driver's side this time. He quickly buzzed down his tinted driver window and began gesturing with his arm/hand and saying something, so I rolled down Sarah's side window (she was a little horrified at first :eek:, not knowing what to expect)... Turns out he just wanted to know what year it (Lil Red) was, and then said that it was a beautiful truck. We thanked him and exchanged smiles and waves, and then each went on our way. I get that a lot... Usually, the first question is "what year truck is it?" :)
Jim

[a5150nut]

Makes me think of Little Nash Rambler Beepbeep Beepbeep

[arveetek]

Makes me think of Little Nash Rambler Beepbeep Beepbeep

LOL! I hadn't thought of that song in years! Thanks for reminding me of it.

https://www.youtube.com/watch?v=ayTJtVzHOLs

Casey

[More Power]

Makes me think of Little Nash Rambler Beepbeep Beepbeep

I don't remember hearing that tune back in the day. It's cute... beep beep...:eek:

Nowadays, with engine/powertrain conversions so popular... I can imagine the fun one could have with a '50s Nash Rambler equipped a supercharged LSA (Chevy 6.2L aluminum 4th-gen V-8) and a 6-speed (556 hp @ 6100).

[More Power]

A couple of questions came up recently about the CheckMate hard tonneau cover I used on Lil Red. So, here are three archive photos that were taken soon after the truck first hit the street, along with some additional information. First, as a way of introduction, this was a hard tonneau (fiberglass top/bottom surface, foam core and aluminum perimeter frame) made by a company called Checker Products, from Benton KY. Unfortunately, Checker ended production some time ago.

A hard tonneau was part of the project because it was needed to complete the look, make the truck more aerodynamic for better fuel economy and performance, and provide more security/weather protection for anything we might haul in the truck bed. Standard cab trucks just don't have a lot of excess room in the cab... ;) Numerous aerodynamic studies have been performed through the years concerning pickup trucks and bed covers. All of them show a significant and worthwhile gain in drag reduction and fuel efficiency improvements.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7114&d=1687797398

The tonneau model shown here was their flush style fiberglass cover sized for our short-bed Sportside Chevy, and which cost $350 in 2004 plus a modest delivery fee. These were available at the time in either white or black gel-coat, that could be left as is or painted (by the owner) to match the color of the truck. I received this tonneau just before the truck went to the body shop for its makeover in April of 2004, which made it easy to get everything painted all at once. The gel-coat finish was a little wavy/textured, so I asked the body shop to spray on a heavy coat of sand-able primer in an effort to get a smooth finish - before spraying on the red base and clear coat. They resisted at first, but in the end, they chose to put some time into the project to make the tonneau finish smoother. Maybe they got some encouragement as their work on the truck progressed and they got a better sense for how the finished project would look. I think they did a great job.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7113&d=1687797398

A variety of options were also available at the time - like quick release hinges (used here), carpeted under-surface, exterior locks, tailgate handle lock, courtesy light, grab handle - and more (that I didn't get). For those who like the bed-liner look, you could have ordered your hard tonneau with a sprayed-on polyurethane finish similar to that used for sprayed-on bed-liners.

The gas-charged lift-struts raise the cover high enough to allow easy access to the bed. Plus, the strut ends disconnect easily, allowing the entire tonneau cover to be lifted off the truck in just minutes. A hollow rubber perimeter seal keeps the weather out and cushions contact with the painted surfaces of the bed rails.

The pair of angled metal tongues mounted to the front of the tonneau slip into cleats screwed onto the truck bed's headboard, providing both a hinge and front mount. With the lift struts removed, simply lift the tonneau to something greater than 45°, then slide the tonneau back and out of the front mounts.

The lower end of each lift strut is mounted to a convenient location in the bed. Instructions were a little fuzzy about strut mount location, but determining where to put the strut mounts just required closing the lid, and positioning a collapsed strut to mark the mount location. I used a dab of red silicone sealant on each screw hole and under each bracket to seal out moisture and to add durability to the assembly.

In addition to the included nylon quick-release straps (that are used here to secure the aft end of the cover), Checker also offered optional key locks as a way to secure the rear of the tonneau. I thought that I might eventually install the key locks, but the straps have been doing a good enough job. And, I could also install an aftermarket tailgate lock, which would provide additional security.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7112&d=1687797398

This photo was taken at the end of May 2004 at the first car show Lil Red attended, showing just how flush the cover sits on the bed rails. Notice that the bed rail pockets had been eliminated during the paint/body work. Judging from the reflection, Lil Red appears to have been in good company at this car show!

The top two photos were taken in May 2005, about a year after installing the CheckMate tonneau. Even today (June 2023), some 19 years since the truck's exterior was finished, I'm still impressed with the look, the quality and functionality of the tonneau cover.

Let me know if you have any more questions.

Jim

[More Power]

As mentioned before, Lil Red and its Duramax/Allison conversion have appeared in at least 8 separate magazines during the first few years after the truck first became drive-able. Shown here are images of the title pages for Part I and Part II of an article I wrote for Truck Trend Magazine in late 2004 and early 2005, which discussed some of the performance features that had been added to the truck.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7475&d=1704322934

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7302&d=1692647380

This next image of Lil Red was included in the January 2006 issue of "Diesel Power" magazine - covering the September 2005 "Weekend on the Edge" event that took place in Salt Lake City, where Lil Red attended.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7301&d=1692647380

This next photo shows the best time that the truck produced at the racetrack during the 2005 "Weekend on the Edge" in SLC. The numbers shown here were produced when the truck dyno'ed 500-RWHP. The truck did produce better times here in Montana using a GTech Pro performance system to measure 1/4-mile times once the RWHP had been bumped up to 632. Exciting times!

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7303&d=1692647720

The following dyno graph represents how the truck performed on the Edge Products dyno the following morning. There were 4 runs, 2 at each power setting. The above track run was run at the higher setting.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7695&d=1722625510

[More Power]

I took this photo yesterday in the parking lot of our local Post Office. As luck would have it, a newer GMC crew cab Duramax/Allison powered truck was parked alongside Lil Red.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7376&d=1694710448

Both trucks are powered by a Duramax 6600 and Allison transmission. Both trucks have identical overall final gearing. One truck produces mid teens for fuel economy and one produces 22-24-mpg at 85-mph. Some of why is apparent.

I wish there was more emphasis on fuel economy for the new Duramax 6600 powered trucks. :eek:

[DmaxMaverick]

....I wish there was more emphasis on fuel economy for the new Duramax 6600 powered trucks. :eek:

There was. Until the EPA/CARB got in the way. Burning 25% more fuel for 5% improved emissions never made sense to me. It started in the 70's.

Nice looking post office.

[More Power]

There was. Until the EPA/CARB got in the way. Burning 25% more fuel for 5% improved emissions never made sense to me. It started in the 70's.

Nice looking post office.

Yes, emissions compliance is a big part of it. So is the "big-n-tall" trend.

Back in 2017 I drove a Ford Budget box truck that had a loaded 16' enclosed box (furniture and household goods) and towed a car dolly with a Malibu on it from Montana to Tucson - about 1300 miles. That Budget truck was equipped with Ford's 5.3L (if I remember correctly), which produced an impressive 11-mpg for the trip. It never overheated and the A/C worked perfectly even with the baking temps we saw along the way - it was late August. At the time, I thought that that level of fuel economy, with that load, makes it hard to justify buying a diesel on a fuel economy argument alone.

Now, in defense of diesel - I wish my 2001 GMC had had its head gaskets replaced before this 2017 Tucson trip. I would have driven my crew cab Duramax and towed as large a box trailer as U-Haul/Budget offered. Sarah would have had to drive her Malibu, but the trip would have been more comfortable and relaxing. Hills and the Interstate would have been an easy run, and the GMC would have produced better fuel economy. But... there are many reasons (that most diesel owners are familiar with), beyond fuel economy, that make a diesel pickup a better choice for hauling/towing.

[More Power]

One topic I'm often asked about concerns the Duramax Conversion Mounts designed here - at TheDieselPage.com.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7576&d=1712865057

The above photo shows an experiment I did early on in the design phase for the motor mounts. I wanted to take the easy way out, and re-use the original clam-shell mount... if I could. Turns out, it was ugly and just wasn't feasible. It would have been a "Rube Goldberg" contraption that wasn't nearly as safe as the design I eventually settled on - below, and it just looked bad. Plus, re-using the clam-shell didn't offer the design freedom I needed in engine placement (height/front/back). In the end I abandoned the idea.

The following photo shows the very first prototype passenger side (right side) mount - that's still in use today.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7416&d=1697475617

This photo was taken in late 2002 during the final phase of the motor mount development. The front clip was still off the truck, and work on the truck's interior and exterior had only just begun. This degree of access provided a great opportunity to get a series of photos showing the Duramax 6600 setting in the chassis - on the new conversion mounts. The pictured passenger side mount (and the driver's side mount) were derived from a set of cardboard facsimiles I produced over a few days with lots of trial fittings and time spent weighing options. There's so much to consider with regard to engine placement: like transmission tunnel clearance, front differential/mount clearance, fan clearance behind the radiator, fan clearance within the fan shroud, firewall clearance, hood clearance, drive-train angle (calculated U-joint angles), as well as aesthetics, engineering and reproducibility.

You can read more about the Duramax Conversion Mounts (https://www.thedieselpage.com/conversionmounts.htm) by clicking this link. Incidentally, these mounts have been tested with up to 632-hp and 1219 lb-ft of torque without any problems. The power/tq figures are mentioned here in response to a question I received just last week about whether these mounts would handle more than stock power.

Before the Duramax was lowered into the chassis for the last time, I installed a set of new GM 1988-98 GMT-400 factory lower mounts (part with the rubber) to replace the tired originals. I had considered installing an aftermarket set of urethane mounts, but didn't want to add variables that could lead to more complications (potential for more engine vibration transmitted into the chassis)... It's been more than 20 years since this photo was taken, and I still think I made the right call.

The Duramax Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm) contains a set of full-size drawings for the original 2002 design passenger side mount (shown above) and the driver's side mount (they are different from one another). However, we're now on our third gen Duramax Conversion Mounts that have been refined in appearance, function and design. The metal pieces are all cut on a CNC water jet with locking tabs that provide perfect jig alignment before welding. Then the best welder I know puts his MIG to good use. Even through Covid, supply chain disruptions and inflation we (my welder, metal supplier and I) have been able to hold the line on cost - for the time being. There's very little margin in selling these mounts. I do it more to help people involved in a conversion. I know how exciting that first drive is... What little margin there is goes back into keeping this forum/web site online, answering your questions and keeping the lights on. In other words, we need your help too.

By the way... The welder I mentioned did a number of fabrication jobs for me when Lil Red's Duramax conversion was being put together. So, he's very familiar with this and other TDP projects completed through the years. He drives a Dodge, but he's still a great welder/fabricator... ;)

Let me know if you have any questions.
Jim

Want to share this forum topic thread with others or help us to get the word out about Duramax conversions? Copy the following link and paste it into another forum post, email, text message or social media site:
thedieselpageforums.com/tdpforum/showthread.php?35210 (http://thedieselpageforums.com/tdpforum/showthread.php?35210)

[More Power]

https://youtu.be/UWI_2Lqv8Wo

This video short was of Lil Red at the Salt Lake City 1/4-mile track in September of 2005. Too much nitrous oxide too soon put the fire out during launch - nitrous is really-really cold. The nitrous was switched off just as the engine began losing rpm, which was followed by a backfire. You can see the white smoke (fuel vapor) stream out the exhaust during launch as the engine spooled down, followed by a "pop" sound in the video (the fire relit on its own before the engine rpms dropped to zero). You may need to replay it a couple of times to identify the pop.

Does it appear to you that after the bad start, Lil Red was gaining on the other truck about 2/3 of the way down the track?

I don't know why the track announcer sounds like he's related to Charlie Brown's parents. The trucks sound more or less normal. This was at a time when cell phone cameras were not as good at taking videos as they are now. Still, I'm glad I have this video. It was taken by a fellow TDP member that evening...

The backfire caused 2 head bolts near cylinder 8 to loosen ever so slightly, and combustion pressure began finding its way past cylinder 8's LB7 injector cup seal, as evidenced by a carbon track appearing at the juncture where the small end of the injector cup passed through the cylinder head deck. This resulted in pressure ever so gradually building in the cooling system over time as the engine ran, to a point of cooling system leaks and cooling system overflow. The truck was still drive-able, though the excess pressure became a nuisance.

Not long after this SLC event, Lil Red posted its highest HP/Tq at a Montana diesel dyno event, even with the "problem" (there's a video of that dyno pull earlier in this forum topic thread). The various engine parts were carefully inspected at tear-down during the head gasket replacement process in 2021. I couldn't see that any additional damage had occurred as a result of not fixing the problem soon after it happened. This excess cooling system pressure could have caused the water pump seal to wear and begin leaking, but the truck simply wasn't driven enough to get to that point. So, the engine is still running with the engine's original factory-installed water pump.

As of the time this post was made, it had been more than 2 years since installing new head gaskets and resealing the injector cups (in late summer of 2021), and by November 2023 the truck has accumulated an additional ~5000 miles without generating any excess pressure in the cooling system. Installing new head gaskets, installing new factory TTY head bolts and resealing all eight injector cups have definitely solved the problem. It's a good feeling to have that problem behind me. The truck is reliable enough now that I'm confident it could be driven from Montana to Miami and back without a problem.

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7469&d=1702927130

You've seen in earlier photos how the truck looked when I received it and how it looked after the body work and paint had been completed. Here are a few photos showing the process of getting from tired to shiny... :) The above photo was taken because the right side bed rail had a big dent in it along with an associated crack in the fiberglass wheel-flare when I received the truck. This photo shows the body work had corrected the problem and was now ready for paint. Also, I had the shop fill the stake pockets in the bed rails.

The bed-side/wheel flares are made from fiberglass, while the bed rails and box are made from steel. The body shop needed to unbolt/remove the fiberglass bed-side to do a good job.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7467&d=1702927130

Here, the body man is at work on the bed rail - with the bedside removed. He spent quite a bit of time on the truck overall. He let me watch some of it. Auto body work is something I wish I'd learned more about when I was a kid. Nowadays, I think about how great it would have been if a talented adult had mentored the teenagers (interested in auto body work) in our small town when I was just getting into the car hobby. We learned by doing in those days, which means I actually painted a couple of cars when I was a teen... The reality was that there wasn't much of an improvement... But, it did keep the soon-to-be Chevy classics (a long list of 1955-1964 Chevy cars) I had at the time out of the crusher.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7470&d=1702927130

The above shows the passenger side of the truck after it had been worked and primed. I bought the cowl induction hood and had it painted the final color you see here the year before, so I could begin some early promotion. In black primer, the hood cost $500 - painting it red added another $500.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7466&d=1702927130

The rear lower corners of the bed-sides were custom fiberglass additions - that allowed removal of the original factory flare-outs. I guess GM wanted to make the Sport-Side bed width match the width of the Fleetside beds - so they could use the same width factory bumper. I always thought those corner flare-outs made the rear look fat... The above is how it should have been designed.

Also, you can see that the new fiberglass roll pan is being fit into place. The body shop made the roll-pan fit and then painted it, but I actually completed the final installation in my shop. Maybe they didn't want to screw the fiberglass to the bed. No fear here! I used about a half dozen button head screws along the top and two on each side (inside lips). I also used an automotive semi-flexible adhesive, in combination with the screws, to secure the roll pan. Hasn't worked loose yet! By the way... the spots appearing in the above image are the result of camera flash and sanding dust.

Incidentally, in the above photo you can see that the truck's light-duty original 10-bolt GM rear axle is still under the truck. At this point in time I was probably working on the new replacement axle, a GM Corporate 14-bolt 9-1/2" 6-lug rear axle with rear disc brake conversion when these photos were taken. And, the yellow Bilstein shocks were likely still in a box at home.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7468&d=1702927130

The final red paint used by this shop is the truck's original factory color. I like this red, and using the same color meant we didn't have to paint the inside details of the doors/cab - or remove the box. Once painted red, it was shot with a couple coats of clear-coat. I wasn't there to see the cut-n-buff, but wish I had been. I'm always amazed by talented body work and paint. It's as much art as it is anything. Jim

PS... Final cost for the body work and paint shown here was nearly $5k in the spring of 2004. This total does not include the cost of the custom cowl-induction hood, custom fiberglass bed mod parts (gray parts in the above photos), new painted factory front bumper, new painted grille, late 1990's C/K model factory mirrors, or the bed's tonneau cover mentioned earlier in this thread.

And by the way... I had already completed the Duramax/Allison and dash conversion by the time these body shop photos were taken, but the seats, door panels and carpet/headliner were still waiting for me at home. A few years earlier I had a bad experience with a different body shop leaving the windows down on a project truck of mine as they did some paint/body work for me, which left the interior covered in a thick layer of sanding dust. So, this time, I took no chances, and simply left most of the interior out of the truck. That said, this auto body shop was different, in that they covered the dash and everything else to keep the sanding dust and any paint over-spray out of the interior and engine compartment. Lesson here... the lowest price quote isn't always the best deal.

To get the stance I was looking for I added a 2" lowering kit to the rear leaf springs once I got the truck home. This helps with fuel economy, performance, road handling and the overall build design I was going for.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7112&d=1687797398

Shiny!

[More Power]

I watched a couple of pickup truck related events on Youtube recently. The first photo here was screenshot from the 2023 Hot Rod Powertour video while the tour was in eastern Tennessee and the other was from a video about a Chevy C10 group event that was sponsored by LMC Trucks. I saw a couple of trucks while watching the videos that made me hit the rewind button.... :)

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7517&d=1707160066

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7518&d=1707160066

Though Lil Red is now 35 years old (but 20 years in its present form), it seems some of the design elements may have appealed to a couple of other truck builders. I think its cool. ;)

Jim

[JohnC]

Oh, those wheels!

[More Power]

Oh, those wheels!

Don't hit any potholes!

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7539&d=1709154546

The power increases eventually reached the limits of the factory Allison. In working with Kennedy and ATS, we came to the conclusion that the "ATS Extreme" Allison would be a step in the right direction. It has been. While the original factory Allison could be made to slip with 500-hp and a power-brake launch at the strip, the ATS has yet to slip, even with more than 600 hp. The torque converter contains a 5-disk pack that provides for a solid connection once locked.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7540&d=1709154546

A note about this image... Originally, I used smoke-tinted covers for both the headlight lenses and turn signal lenses. I would then remove the smoke tinted headlight covers if/when the truck was driven in the evening or at night (very rarely). The covers were employed only during during the daylight hours. Because removing/replacing the covers was a royal PITA, I have since replaced the tinted covers with DOT tinted headlight lenses and tinted turn signal lenses. I did give up a small amount of illumination in exchange for a better match for my patience. ;)

A local friend who also just happens to own a mechanics garage (and is a transmission expert), worked with me to install the new ATS Allison. The lift makes this sort of thing so easy, when compared to a transmission floor jack and jack stands...

Shift quality while using performance programming was pretty "performance oriented", sometimes producing a little "bark" from the rear tires at gear changes while on local highways. Who can resist using a little pedal? ;) But, when toning down the ECM programming to near stock levels, the ATS Allison gets real close to factory Allison shift quality.

I've not had any code setting with this transmission - or any other problem. There's only about 12K miles on it since installation, and the ATF fluid remains nice. The transmission has seen only a couple of dozen 1/4-mile runs and a similar number of dyno runs so far, plus highway driving. But, I do plan to service the transmission this coming spring - new spin-on filter and pan filter, plus a fluid drain/refill. I'll report back once that's been completed... if we find anything unusual. Jim

[a5150nut]

Are you running Kennedy's tune on your truck? Or a custom version of his?

[More Power]

Are you running Kennedy's tune on your truck? Or a custom version of his?

Currently, the truck has a Kennedy EFI-Live switch-selectable tune - a stock power setting with fuel economy, and a +100 hp setting. Time flies, but this programming was added not all that long ago. Jim

[a5150nut]

How street-able is the 100 hp setting?

[More Power]

How street-able is the 100 hp setting?

Haven't used it enough to form an opinion. It definitely brings a bit more "sport" to the table than the stock setting. It would be interesting to compare the two current power settings on the dyno. I do know that the race programming from before was a bit too sporty for the street - that is, once I got past the "watch this" phase. ;)

[a5150nut]

I was curious about the 100hp been thinking it might be on my bucket list
I'm sure John removes the speed cap too. My son had a 6.0 built and we were on the way to Winimucka from Carlin NV he dropped back about 5 truck lengths and nailed it. When he got up to me I nailed mine. matched his speed, then started pulling away. Up till I hit 94 and the computer started de-fueling my foot

[More Power]

I was curious about the 100hp been thinking it might be on my bucket list
I'm sure John removes the speed cap too. My son had a 6.0 built and we were on the way to Winimucka from Carlin NV he dropped back about 5 truck lengths and nailed it. When he got up to me I nailed mine. matched his speed, then started pulling away. Up till I hit 94 and the computer started de-fueling my foot

I haven't pushed things too far with the latest programming. I seem to remember talking with John about the engine rpm and vehicle speed limit settings. I asked for 4000-rpm as the programmed max engine speed, and we talked about removing any sort of programmed vehicle speed limiter. So, with an engine rpm limit currently at 4k, and with 2000-rpm currently producing 80-mph, the theoretical vehicle speed limit is.... a little scary. I've not tested the theoretical. ;) I heard once that "there are old pilots and there are bold pilots. But, there are no old-bold pilots." :)

[More Power]

This video was produced some years ago, before diesel performance programming could produce power without smoke and while tires were a bit less expensive than they are now. ;) Mind you, something similar to what's shown here can be seen today on nearly any performance automotive cable program or related Youtube channel. So... Lil Red hasn't produced smoke in years and tires are currently viewed as a more longer term investment...


https://www.youtube.com/watch?v=EO46o2_VrlY

Except for imagining vvrrrooommm sounds, there is no audio. However, no pedestrians or cute bunnies were harmed in the making of this film. :o

The following image was shot a few months after the above video was taken, only this time I was using a KennedyDiesel.com EFI-Live program that allowed the truck to dyno 500-rwhp. As you can see, there is no visible smoke shown here at the beginning of a 1/4-mile run. ;)

I was likely using a Van-Aaken performance module when the smokey burnout video was made. I liked that in-line module when used at lower power (no smoke) settings, and I used it for years in my 2001 GMC Duramax crew cab where it could smoothly produce more than 400 rwhp without smoke.

https://www.thedieselpage.com/features/atstrans08.jpg

Back in the early days of the Duramax I answered a few emails from young guys who wanted ideas for how to get their truck to produce more smoke... I tried to discourage the idea...

[More Power]

When beginning a project as complex as a Duramax conversion, it's helpful as you work through the project to use checklists, and then concentrate on one or just a few steps at a time. A person can become bogged-down and discouraged when contemplating the entirety of the project. Again, just concentrating on a few steps at a time helps to keep you focused, and allows you to see and measure progress in real terms.

When Lil Red was still in the planning stages, and later while actually working through the conversion, I created many lists that I used to help keep me focused. Shown below is just one of those lists (yes, I kept them all). Some of the lists, notes and hand-drawn diagrams were later refined and then included the "Duramax Conversion Guide". Aside from helping me as the conversion was taking shape, some of this information could be helpful if a problem appears months/years later. Knowing the details can aid in troubleshooting.

http://www.thedieselpageforums.com/photopost/data/500/checklist002.jpg

When taken as bite-size chunks, the project becomes more doable for most people. And a list helps to keep you focused.... ;)

Jim

[More Power]

Here's an article I wrote for the 2007 issue of Diesel World magazine (involving Lil Red), which wraps up a discussion we were having at the time about Duramax Diesel performance - performance that didn't require tons of money, was relatively easy to do and didn't involve a lot of modification. The actual dyno performance data is included here too.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7552&d=1712087851

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7551&d=1712087851

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7550&d=1712087851

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7549&d=1712087851

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7553&d=1712089600

Let me know if you have any questions.
Jim Bigley

[More Power]

Early in Lil Red's history we visited a number of tracks here in the Northwest, from Salt Lake to Abbotsford, BC. The following photo was taken at the Spokane Raceway in (I think) mid summer 2005. That day was more of a shake-down, experimenting with different products as well as trying to find the best way to launch the truck (2WD, 4WD, powerbrake light/hard...). 2WD didn't work well at all... And, I didn't have nitrous on it then. This early period was still pre EFI-Live, and the truck was still running with the original Allison, so the day turned out to be more about learning how to run the truck rather than make any real progress in performance. However, it was still a super fun day and I was able to see how well the truck/Duramax performed when closer to stock power. Plus, I got to spend time with my son and talk to other enthusiasts at the track.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7586&d=1713309128

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7596&d=1713900522

Rear Disc Brake Conversion
-
for GM's 9-1/2" 14-bolt Semi-Float Rear Axle
Part I - From the archive - an in-depth look at the rear disc brake conversion used in Lil Red The new GM 9-½" semi-float rear axle has been installed, and to improve braking ability, we've decided to upgrade to disc brakes. Rear discs help with two important areas - the reduce un-sprung weight and they increase stopping ability. Demands on the braking system increase as vehicle speeds increase. Stopping can be more important than going fast.

All of the brake components used in this conversion are factory GM 1999-2003 model-year K1500 parts bought from either a local GMC dealer or from Spalding Auto Parts in Spokane, WA. The only special items not available from GM are the adapters needed to adapt the original axle flanges to the new disc brake backing plates.

The above photo shows a complete set of parts for one side - rotors, assembled backing plate, caliper, caliper mounting bracket, flex hose and related hardware. Not shown is the backing plate adapter and related bolts. We hope to have the newly fabricated flange adapters ready for part II of this article.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7595&d=1713900522

The factory cast-iron vented rotors shown here are about $60 each and are designated for a "Pickup JC5/JH5 - Vacuum" braking system, having a nominal diameter of 325-mm x 20-mm thick (12.8 x .787"). Inside each rotor is a parking brake mini-drum.

Note: You may need to reduce the outside diameter of the axle wheel flange to allow the axle flange to fit flush within the inside face of the rotor. I used an angle grinder with the truck's engine idling in drive. Both rear wheels/tires were off the truck, and the rear axle was supported by a pair of jack stands. I used an 8x16" concrete block to steady the angle grinder - to get a near perfect reduction in outside diameter of the axle flange. It only needed a very small amount of reduction.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7592&d=1713900522

The disc brake backing plate assembly (pn-15206075) came as a fully assembled piece, with the parking brake components already installed. The parking brake shoe is a one-piece affair, with cable actuated and adjustable shoe engagement, to compensate for fit and wear over time.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7593&d=1713900522

The above shows the rough working drawing used to fabricate the axle flange adapters. The dimensions shown here will exactly center the brake caliper over the brake rotor.

The square plates for each adapter are the same size, but are clocked differently to correctly locate the brake calipers at the front - when viewing both left and right sides. The points of the square end-plate that bolts to each disc brake backing plate are positioned at 12 & 6 o'clock. The square end that bolts to the existing axle flange (welded to the axle housing) should be positioned 5° nose down for both the right and left side of the truck. This means that the adapters for both the right and left sides of the axle are different from one another.

See Part II below...

Jim

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7602&d=1713901757

Disc Brake Upgrade - Part II
A rear disc conversion generally offers better braking ability - both when dry and especially when wet, weighs less than most drum brakes, sheds heat faster - more fade resistant, and discs just look way cooler... Our rear disc brake installation is now complete. Read on to find out how they look and stop.

Note: I spray painted the outward facing areas of both rotors (except for the rotor surfaces that make contact with the brake pads) using a high-temp silver automotive paint. The rotors are made using a rust-able cast iron. The silver paint keeps things looking good.

We converted to rear disc brakes primarily because we had upgraded to a stronger rear axle, were using a larger tire/wheel combination, and we needed better rear braking than was provided by the original rear drums. The sum of the new rear disc brake components provided no weight savings when compared to the small 10" drums used on the original 10-bolt rear axle, but in addition to the coolness factor, the rear braking ability has definitely improved - more about that later.

There are a number of companies that offer disc brake conversion kits for 1500/2500/3500 series GM pickup trucks and SUV's currently equipped with rear drums (see list at end of article). A DIY project like this, when using all new GM parts + fabrication, will cost about the same as a commercial kit. I chose to use all new OEM parts for ease of maintenance and when buying future replacement parts. Plus, a functional and effective emergency brake was necessary because this truck will be trailered occasionally. The e-brakes included with most aftermarket disc brake kits I've seen don't inspire a lot of confidence.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7597&d=1713901757

Fabricating the offset brackets was the most time consuming portion of the project. I had a local fab shop build these for me, using a drawing I supplied. The ½" steel end plates were cut from sheet using a water jet CNC, and a section of steel pipe was located that fit the OD of the axle tubing.

Once back from the fab shop, I spent some time drilling and tapping the sixteen holes for the 12mm bolts, then squirted on a little black paint.

It should be noted that the dimensions listed on the drawing fit the 1997 model-year 9-½" 14-bolt semi-float axle used in our buildup. If you are installing similar disc brake components on the smaller GM 10-bolt rear axle, you may need to adjust the thickness of the offset brackets to compensate for a different axle flange location. Flange offset bracket thickness is correct when the rotors are centered in the assembled disc brake pad brackets.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7598&d=1713901757

The newly fabricated offset bracket has been bolted onto the axle flange using four 12mm bolts, each torqued to 100 ft/lbs using thread locker. Correctly clocking the square ends was important to transfer the correct orientation to the disc brake backing plate.

I drilled out the threaded holes in the original axle flange (using a ½" bit) to allow the 12mm bolts to pass through and then thread into the new brackets.

This bolt-on installation has proven to be plenty secure. A lot depends on the quality of the welds. I had a pro do the welding for me.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7599&d=1713901757

The disc brake backing plate has been bolted on using four 12mm bolts, each torqued to 100 ft/lbs using thread locker. The calipers and disc pad brackets are bolted onto the forward-facing side of the backing plate, 9 o'clock on the driver's side and 3 o'clock on the passenger side (passenger side shown).

The axle shafts need to be removed when installing the offset brackets and disc brake backing plates. It's a fairly simple job to remove the differential carrier pin, slide the axle toward the center, then remove the axle-retaining C-clip. The axle will then slide out. Be a little careful not to damage the wheel bearing seal.


https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7601&d=1713901757

The original steel hydraulic brake lines were carefully reshaped by hand to fit the disc brake flex-line mounts. The truck's original e-brake cables can't be modified to work with these GM disc brakes due to the new rear facing e-brake cable anchor (1) and actuation lever (2).

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7605&d=1713901903

To match the new disc brakes, you'll need a set of e-brake cables made for a similar wheelbase 1500 series truck (i.e. 2000 model-year, models 03, 06, 53 - new style 4x4). These loop over/under the axle, then sweep around to make the connection on each side.

The above driver's side photo shows the e-brake cable sweeping around and anchoring to the shock mount, then running under the axle tube, before sweeping up and through the wire loop bolted to the frame.


https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7604&d=1713901903

On the passenger side, the e-brake attaches to the rear facing side of the brake backing plate, loops away and then is anchored to the axle tube, before sweeping up and over the pumpkin. The cable mount shown in this photo that secures the cable to the axle tube is simply a steel strap, but you can weld on a tab if you have access to the right fabrication equipment.

A metal clamp secures the e-brake cable from one bolt on the differential cover. From there, the cables sweep across and forward through the wire loop on the frame.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7603&d=1713901903

The forward ends of both e-brake cables mount to a fabricated bracket that is bolted to the frame. I may tinker with it a bit over the next few months.

A 2" long piece of ½" square steel tubing was used to provide an anchor point for both cables that can rotate slightly to accommodate a slight misadjustment between the right & left e-brake shoes. This is similar to how the factory parts operate.

Articles have appeared in various truck magazines that mentioned a few potential complications when converting from drums to discs. First, some recommend a new brake master cylinder designed for a 4-wheel disc system, to either provide more fluid volume for the larger rear disc brake caliper pistons or to modify hydraulic brake pressure. Secondarily, they mention that the front/rear brake proportioning valve may need to be modified or replaced for some installations. I had installed a new brake master cylinder and hydraulic brake booster when the truck was assembled a year ago, and I did not want to buy replacements. After breaking-in the rear rotors/pads and performing a few hard stops, I feel that (for this particular truck and installation) a new master cylinder is not necessary, nor is replacing/modifying the proportioning valve. The current front/rear brake proportioning appears to be nearly ideal for this lightweight truck.

I lucked out, but some of the factors that contribute to correct brake proportioning include the weight of the vehicle - especially over the rear, condition of the brake master cylinder and hydraulic brake booster, wheel & tire combination and type/composition of the disc brake pads themselves (some are more aggressive than others). I installed the NAPA Premium Disc Brake Pads #AE-7662-M, which are asbestos-free and are supplied with new anti-rattle clips.

An alternative to retrofitting discs to your existing rear axle would be to locate a suitable disc brake equipped rear axle that had been installed in a newer vehicle. If you can locate a replacement disc brake equipped rear axle in good shape and with the correct gearing, your total cost could be somewhere in the same general price range as a rear disc brake conversion kit. I considered going that route, but unfortunately, GM didn't produce a six-lug disc brake equipped rear axle with the 9-½" ring & pinion that I needed (all current GM disc brake equipped 9-½" rear axles now have 8-lugs, and are used on GM's light-duty ¾-ton trucks).

If you have a drum brake equipped heavy-duty ¾-ton or 1-ton truck, you'll find a variety of aftermarket disc brake upgrade kits currently available for your rear axle. In addition to the braking advantage, disc brakes would provide a worthwhile weight savings due to the much larger drums used on the HD vehicles. Incidentally, if you maintained the functionality of the RWAL (Rear Wheel Anti-Lock) braking system for your conversion, this disc brake conversion won't affect the performance of the anti-lock system. This is because the RWAL uses the vehicle speed sensor to determine whether the rear wheels are rotating during a hard brake application. There are no individual rear wheel speed sensors used by the truck's original braking system.

Would I do it again on a ½-ton? Tough call, but I would if there was a need improved braking performance or simply wanted more modern disc brakes on the rear axle. Appearance is important too... They do look cool! TDP

Continued next post...

[More Power]

1999-03 Pickup JC5/JH5 K1500 OEM Six-Lug Rear Disc Brake Components:



These parts fit models 03, 06, 53 - new style 4x4
Aluminum Single Piston Caliper Right: #18040088 List $188.02 Discount $131.61
Aluminum Single Piston Caliper Left: #18040087 List $193.42 Discount $135.39
Brake backing plate: #15206075 $54.25 ea (2 required)
Brake Pad Guide bracket: #18040090 $59.25 ea (2 required)
Brake Flex-hose Right: #15102334 $24.26
Brake Flex-hose Left: #15102333 $24.26
Caliper Guide pin: #12530697 $4.40 ea (4 required)
Caliper Guide pin grease seal boot: #12530703 $3.68 ea (4 required)
Bolts: #15007007 $2.85 ea (16 required)
Bolts: #15012506 $0.99 ea (4 required)
E-brake Cable Left: #15084208 $22.00
E-brake Cable Right: #15084209 $29.83
The new factory cast-iron vented rotors shown here were about $60 each and are designated for a "Pickup JC5/JH5 - Vacuum" braking system, having a nominal diameter of 325-mm x 20-mm thick (12.8" x .787"). These were purchased from Spalding Auto Parts in Spokane, WA - 800/366-2070 www.spaldingautoparts.com (http://www.spaldingautoparts.com).

GM pickup & SUV Aftermarket Disc Brake conversion sources:
AP Racing (aka Brake Pros www.brake-pros.com (http://www.brake-pros.com))
888/266-0696
www.apracingusa.com (http://www.apracingusa.com)
Dynatrac
714/596-4461
www.dynatrac.com (http://www.dynatrac.com)
Stainless Steel Brakes Corporation
716/759-8666
www.ssbrakes.com (http://www.ssbrakes.com)
Wilwood Disc Brakes
805/388-1138
www.wilwood.com (http://www.wilwood.com/)

[More Power]

It's been a long time since I polished the original tail light lenses on Lil Red. After polishing them the first time, they photographed well enough for the promotional photos I needed. They weren't perfect, but they were good enough, considering how much other stuff still needed to be done on the truck during that time. But that was then, and this is now - and the tail light lenses needed attention once again (see below). So.... instead of polishing them this time around, I thought I'd take the easy way out and just replace them.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7608&d=1714494527

Yes, I could have polished the original lenses shown here on the left... yet again. I have the polish and the buffer, but the foam rubber gaskets that seal the lenses against the truck have deteriorated somewhat, and the foam perimeter gaskets are porous enough to hold grime and/or wax, which makes them tough to keep clean.

Visually, one of the things I tend to notice about new vehicles is the shiny "jewel-like" faceted appearance of head/tail light lenses. New lenses just look... well... "new". Spiffy lenses improve the look of any truck.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7607&d=1714494527

I've used this "Eagle Eyes" brand of lenses before - I have a set of headlight/park lenses on the shelf for my 2001 GMC. The quality is pretty good. The new tail light lenses shown here were made in Taiwan and are priced reasonably via Amazon Prime... a little over $50/pair delivered. Being the hoarder that I am, I'll likely hang onto the original lenses for a while longer. ;)

Jim

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7621&d=1716398605

These photos show the installation of a modified stock 1994-2002 Dodge intercooler - to give you some idea what the installation looks like in Lil Red. This Project Update will introduce you to the intercooler installation process, and illustrate some of the modifications necessary to install a 1994-2002 Dodge Cummins intercooler in a 1988-98 C/K pickup truck or Suburban.

As it turns out, the Dodge Cummins intercooler core dimensions are exactly the same as the core used in a stock 2001-2004 GM Duramax powered 2500HD/3500 truck. At the time I put Lil Red together, I could not locate a used/salvaged GM intercooler, and was already over-budget on this project, so I wanted to cut costs where I could. A factory new GM intercooler was more than $600 at that time. So, the only reason I bought and modified a Dodge Cummins intercooler was because I was able to buy one on eBay for a lot less. A GM factory Duramax intercooler would have been my first choice otherwise, even though it too might need to be modified.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7622&d=1716398605

The above photo shows what the modified Dodge intercooler looks like installed on the truck, but before the hood latch support had been modified.

This intercooler was purchased from a seller on Ebay. I had been watching Dodge intercooler auctions for a few weeks, before deciding to actively engage in the buying process. Some of the offered intercoolers were removed from wrecked or damaged Dodge trucks, so you need to evaluate any intercooler offered to determine whether it remains usable or whether the damage was more cosmetic in nature. The one I bought did have some cosmetic issues, but was structurally sound and leak-free. Based on the auctions I monitored, you might expect to pay anywhere between $150 and $400 depending on condition for a usable Dodge Cummins intercooler and the whims of your bidding competitors.

The Dodge IC core is approximately 15-3/8" tall, a couple of inches shorter than the available space in front of the radiator.

The IC core is a little more than 2" thick, and will fit fairly well behind the hood latch support bracket in the space formerly occupied by the A/C condenser. The hood latch bracket must be modified to allow for a modified A/C condenser to fit ahead of the intercooler. I could show the A/C condenser mods in a future update if anyone would like to see how I solved that problem. Can't live without A/C... ;)

Aside from being 15-3/8" tall, the core is also 36" wide, not counting the bulk of the end tanks. A 36" wide core closely matches the radiator core width, and works well with the C/K OBS (Old Body Style) radiator core support. The total width, including the end tanks wound up being about 45-½".

These photos show the mods I made to the aluminum end-tanks of the intercooler. As received, the Dodge intercooler's 3" inlet/outlet would need to penetrate the box-sectioned structural member on each side of the radiator core support. I decided not to weaken the radiator core support, which meant modifying the intercooler - i.e. moving the intercooler's inlet/outlet to be outside of the radiator core structural supports.

Widening the intercooler end-tanks required adding material - I used 1/8" aluminum sheet material.

Jim

[More Power]

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7626&d=1716488941

This image shows more detail about how the intercooler end-tanks were modified. The intercooler's inlet and outlet were moved outward to clear the boxed steel sections of the radiator core support, and then the end-tanks were modified to help provide more clearance for the head/park lamp assemblies. A 4" hole needs to be cut in the radiator core support where the intercooler's inlet/outlet pass through.

I made all of the cuts/mods to the original intercooler, then took it and the various pieces to a metal shop for aluminum TIG welding. If doing this again I'd buy my own TIG welder and learn how to use it. In the end there would be no labor charges and I'd still have the TIG welder... all for about the same final cost. And incidentally, once all of the mods were completed I flushed water through the intercooler in each direction several times in an effort to remove any debris that might have collected internally during the process of modification. ;)

I used the GM factory intercooler hoses, clamps and aluminum tubing produced for a 2001 model year Chevy/GMC equipped with a Duramax 6600. If you have a donor vehicle that'll provide all this, you're golden. You don't have to use the original factory parts, but they will make it just a bit easier. The factory aluminum intercooler tubing will need to be extended because of the widening of the intercooler inlet/outlets. This is a relatively easy process. I used 3" aluminum agricultural sprinkler pipe to provide the extension material. I still have about ~8' of this pipe laying around... if anyone needs some. The Conversion Guide shows how/where to add the extensions.

Of course, there are alternatives with regard to intercoolers. You could search for a generic intercooler core (https://duckduckgo.com/?t=ffab&q=intercooler+cores&ia=web) from an online source that suits your installation, then modify it as/if required. We did that very thing for a 6.5L diesel Suburban in a book published by The Diesel Page (https://www.thedieselpage.com/65bookiii.htm) a few years ago... see link. At the time, the total cost, which included the core, all of the hoses, clamps and aluminum tubing cost about $400 total. So, you don't have to begin with a Dodge or GM intercooler. A generic intercooler core just needs to be sized for a diesel engine approximating the displacement of the Duramax, and of course fit into the available space.

In addition, I know of at least one Duramax conversion running without an intercooler. An owner in Canada used our mounts and Conversion Guide, but chose to avoid the installation of an intercooler because his use for the truck would be mostly light-duty. Personally, I'd still want an intercooler because of the ~20-psi boost pressures and the heat load that creates, but the installation in that Canadian truck shows that a conversion can work without an intercooler in certain light-duty situations. It should be noted that running without an intercooler while towing heavy could produce dangerously high EGTs that put the engine at greater risk. Plus... the engine control module (ECM) monitors intake air temperature, in part to help protect the engine. Excessively high intake air temperatures will cause the vehicle's ECM to defuel the engine - reducing power. It's worth the trouble to install an intercooler, even if you don't plan to use the truck to tow.

How is the intercooler mounted?... you might ask... The intercooler shown here is setting on 2 inch wide 3/16" thick rubber strips that had been glued onto the radiator core support using silicone caulking - to the horizontal and vertical surfaces where the intercooler core made contact. You can see small portions of the strips I'm talking about in the above image. The modified hood latch assembly then clamps the intercooler to the radiator core support - using rubber strips as cushioning. It's been a successful and solid mounting strategy for a long time... although, if my truck were driven on lots of rough road/off highway use, I'd consider welding some beefy 1/4" thick aluminum mounting tabs onto the intercooler core end-tanks that allow bolting it to the radiator core support using rubber-isolated hardware - along with the rubber cushioning strips mentioned here.

There are always different ways to "skin a cat". You may have a different way of completing one of these projects. If nothing else, what's shown here is simply one way, albeit a successful way, that describes how I installed an intercooler in my truck. Project philosophy here in TDP always includes performance, reliability, cost, reproducibility and of course appearance - all important factors.

Beyond the intercooler - there is another related conversion hurdle I faced soon after completing the intercooler installation, and I may show that solution here in a future update... the A/C condenser installation. I'm really happy with the modified A/C condenser I installed - it's solid, reliable, works great and looks professional. After the initial installation of the A/C system and R-134A charge, it's not needed any attention in the years since. Let me know if you'd like to see more. --- Jim

https://www.thedieselpage.com/duramax/1998LBZ09c.jpg

On edit: The above image appeared in a article produced by The Diesel Page a while back, showing Blake Twiehaus's 1998 Chevy K1500 LBZ conversion. Blake used a Dodge Cummins intercooler like I did, but he chose not to widen the inlet/outlet. Instead, he modified the boxed sections of the radiator core support to accept the narrower-original width of the intercooler's inlet/outlet, while maintaining the radiator core support's structural integrity. Your can read more about Blake's conversion here: https://www.thedieselpage.com/duramax/1998LBZ.htm

We need your help too! Would you like to share this thread with others or help us get the word out about Duramax conversions? I hope so. Copy the following link or open the QR code, then paste it into another forum post, text message, DM, email or social media site:

thedieselpageforums.com/tdpforum/showthread.php?35210 (http://thedieselpageforums.com/tdpforum/showthread.php?35210)

Thank you!

[arveetek]

Thanks for all the info, Jim! I, for one, would like to see the A/C condenser modification info.

Casey

[More Power]

Lil Red had been on the road and drive-able for about 12 months by the time the following photos were taken. This means I had driven it through the previous summer (and The 2004 Diesel Page Rendezvous) without air conditioning. It was seriously hot that summer, and I knew that Lil Red simply had to have air conditioning going forward! One summer was enough to tell me I didn't want a repeat.

By the time the truck became drive-able the year before, I had a pretty good idea how I would complete the A/C installation - I just needed to move through the process of modification/installation. And, I could lean on a friend and automotive A/C expert from Tampa, Florida (Gordon Marks) who answered all of my questions and even loaned me some of his hose making tools and supplies during this process.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7680&d=1718213424

The above image shows the newly modified hood latch bracket, made to accommodate the added space required by the intercooler and A/C condenser. It was all TIG welded together. Most of the individual metal pieces used here for the hood latch bracket mod/extension were made from rectangular steel tubing.

The long section of rectangular steel tubing was notched to allow it to extend 3-4" up the back side of the hood latch portion - to provide additional structural rigidity. The bottom of the new hood latch bracket (that bolts to the bottom of the radiator core support) includes a flat steel pad large enough (about 3" wide x 3" tall x 1/8" thick) to clamp the bottom part of intercooler to the radiator core support when bolted on. The upper portion of the modified hood latch bracket is likewise used to clamp the top of the intercooler against the top of the radiator core support. A 1/8" thick rubber strip was used wherever the modified hood latch bracket assembly made contact with the intercooler.

Note: Moving the long section of the hood latch bracket a couple of inches farther forward meant the lower/center attachment mount for the grille will also need to be shortened by the same amount. In Lil Red I simply measured how much to remove, cut the plastic grille mount by that amount, then pop-riveted a 1/16" thick aluminum 90-degree angle onto the shortened plastic grille mount to accommodate the new dimension. Then, I drilled a new hole into the rectangular steel tubing on the modified hood latch assembly (with nylon insert, like OEM) to attach the shortened grille mount. Easy...
--------I'm not using an air/ATF cooler - just the cooler inside the radiator. This lightweight truck doesn't need the additional cooling... plus the Allison has a deep-finned pan. On a hot day, the Allison runs at engine temperature around town, but drops some on the highway. If your truck will be used to tow, I'd install a factory ATF cooler in the upper area just to the right of (passenger side of) the hood latch mechanism. There should be enough room there. You'll have to fab some bracketry, but that should be easy for you at this point. Or... you could put a different shaped aftermarket ATF cooler in the area behind the holes in the bumper... Likewise with the smaller power steering cooler.

I bought a brand new factory GM A/C condenser for this project - made for the model year of Lil Red, then modified it to fit. It wasn't that expensive... surprised me.

Incidentally... The new condenser arrived without any paint on it... just raw aluminum. I initially wanted to spray on a nice layer of satin black paint, but in the end I just dusted on a thin layer to make it less visible through the grille. Paint can act as a thermal barrier, and I didn't want to hamper the condenser's ability to reject heat. So, if the paint looks a little thin here, that's why. The steel brackets, on the other hand were removed and properly painted before final assembly. I also used thread locker on the sheet metal screws used to fasten the new brackets to the ends of the condenser.

The 3-axis position of the actual hood latch components couldn't be changed (hood latch, safety catch). The intercooler installation forced the condenser location to be father forward than the original had been. Mounting the condenser farther forward meant the condenser couldn't be as tall as the original. Shortening the condenser required removing the top 4 aluminum cross tubes along with the cooling fins that covered them. What's described here is the best way I discovered to modify the A/C condenser.

Once I knew how I was going to mount the condenser and knew what mods were necessary, I used a 1/16" thick 4" diameter cut-off wheel on an angle grinder to carefully slice through the delicate fins just beneath the 4th cross tube. This worked well, but go slow, the aluminum cross tubes are thin walled and easily damaged. The remaining stub ends of the cross tubes on the far right side (passenger side) of the condenser were left long enough to allow the stub ends to be rolled over and crimped, followed by aluminum solder/welding. The stub ends that you need to solder/weld closed should be left long enough to account for a flub or two (i.e. the need to re-cut square, fold over, crimp and re-weld). The tubing is pretty thin-walled and delicate. I used a propane torch for this, and I practiced for quite a while on the excess tubing that had been removed earlier. You can buy the torch and flux-core aluminum welding rod at Harbor Freight.

Removing most of the top 4 cross tubes and their fins to allow the condenser to fit, and then soldering/welding the ends of the tubes closed was the most tedious part of this. Honestly, I didn't know if this sort of modification would work when I began the condenser installation. But, in the end I didn't mess up the new condenser, and it installed nicely. Practicing your aluminum soldering/welding on the leftover condenser tubing you removed is essential... dare I say required. It took me a while to learn how to do it without melting the tubing.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7678&d=1718213424

The above shows one of the bottom corners of the condenser, and how I made a bracket mount. The bracket is made from 1/16" x 1" wide steel strips bought from a local Ace Hardware store. The mounting bolt hole I used here, at the bottom of the new bracket (sorta behind the wiring loom), was one of the mounting locations for the original condenser. The right/left sides of the new condenser are mounted tight up against the intercooler, so I used a layer of dense double-sided foam tape to separate and cushion the sides of the condenser where each rested against the intercooler. You can sorta see the white strips talked about in these photos. The dense double-sided foam tape I used came from a friend of TheDieselPage.com who owns a local auto body shop - though I only peeled the backing off one side (didn't want it to stick to the intercooler). The tape is made to attach emblems and trim onto cars... I imagine this tape can be sourced through retail outlets that sell auto paint and body supplies.

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7679&d=1718213424

The upper mounts were constructed as shown above - similar to the bottom mounts. The top most mounting bolt (behind the yellow arrow) was one of the bolt hole mounting locations used by the truck's original A/C condenser. In fact, all four corners of the condenser used the original mounting bolt location.

As mentioned earlier, the A/C system has worked very well since the initial installation/R-134a charge in 2005. It's not needed a recharge, a top off or any other service. In addition to installing a brand new condenser, I also installed a brand new accumulator that mounts onto the firewall, in part because I was converting the original refrigerant used in this truck from R12 to R-134a - I wanted make sure there wasn't any debris or non-compatible compressor oil left in the system. Even on +100 degree days, the system can easily maintain comfort inside the cab.

Because I was adapting a new style A/C compressor to an earlier truck, I needed to make a couple of hose assemblies. This was accomplished by using some new hose lengths and appropriate fittings, assembled using an A/C hose crimping tool. All of these items can be acquired online for not a lot, and Youtube will show you how to use them. Not hard! Contact me via email if you need additional tips.

In the end, the cool factor arrived just in time!
Jim

[More Power]

https://youtu.be/8KaAONkAUCY

A bit hyperbolic perhaps, but this new video asks the question... "Is this the best Duramax Swapped OBS Chevy K1500?" Included here in this video is some basic performance discussion, and you'll learn more about what Lil Red used for performance products when the truck was at the track...

You can help our video channel to grow and reach more people! Please subscribe to our YouTube channel - run your mouse cursor over the little circle truck image in the upper left of the video shown here to see the subscribe button.

I recommend that you create a YouTube account, if you don't already have one. It's easy and free to register at YouTube.com, plus you'll be eligible for free stuff here in The Diesel Page before long. Later this year we'll begin offering all member-only online content here at TDP (https://www.thedieselpage.com/password.htm) free of charge to those who are subscribed to our YouTube channel. Your YouTube account name will be linked to the free access list. Just send me your YouTube user name using the "Contact Me" link in my signature below to gain access.

TDP's long-term goal is to produce more free content videos. Some of these videos will be derived from the several books we've published. The first book to be transformed into a video series will be the "Duramax Service Guide" (https://www.thedieselpage.com/duramaxdieselserviceguide.htm). This book is, in my opinion, the most valuable book we offer.

Where are we are currently in the Service Guide series? The first two videos in the series have already been published and are now available as videos - an Introduction to the Tools, Supplies and Procedures (https://www.youtube.com/watch?v=20JXJx-luNQ&t=2s) that are necessary to begin a project like Duramax 6600 LB7 injector replacement (https://www.youtube.com/watch?v=QQ1D1FUk1zs), head gasket replacement (coming soon), water pump replacement and more... We hope you'll like them!

The 6.5L Diesel won't be left out. More about the 6.5L Turbo Diesel Blazer as well as segments from the 6.5L books will be featured in video format as often as schedules allow.

Subscribing will ensure you don't miss any new videos. As always, your input, suggestions and advice are all important.

Thx,
Jim

[More Power]

Here's an article I wrote for the May 2006 issue of Diesel Power Magazine involving Lil Red, which details the installation of a performance ATS Allison. This transmission has been in Lil Red all this time since. There have been no codes or slips detected. - Jim

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7708&d=1725475926

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7709&d=1725475926

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=7712&d=1725476948

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I used a TH400 auto transmission bolted to the LB7 during the first trial fitting sessions in Lil Red's chassis. The TH400 was lighter than the Allison and a bit smaller - easier to manage when dealing with a minor transmission tunnel clearance puzzle.

As you can see, the earlier Chevy/GMC transmission bellhousing bolt-pattern is the same as the Allison, and (though not shown) the bolt pattern for the torque converter is the same too. This design allowed GM to utilize the Duramax in the van application with the 4L80-E automatic transmission (250-hp/440 lb-ft). Incidentally, GM Powertrain's 2000/2001 Pikes Peak C1500 race truck (GMT-800 body style) was also equipped with an LB7 Duramax and race-built 4L80-E. That engine was producing more than 600-hp, as I recall. Jim