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

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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 and many thousands of miles? 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 these questions and a lot more right here in this forum blog, but I recommend first watching the video linked above, then continue reading. The video linked above will 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. To help make it easier, we offer in-house designed Duramax Conversion Motor Mounts that allow for a bolt-in swap.



This photo was taken in 2002 just after receiving the brand new Duramax 6600 crate engine directly from GM Powertrain, along with an Allison 1000 transmission and NV-263 push-button shift transfer case. Updating the exterior of the truck began soon after.

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.

In addition to the K1500 truck featured here, we also completed a 1987 Chevy C30 Square Body Duramax here at TheDieselPage.com. That 1987 Chevy C30 diesel swap is one of many conversion projects we've been a part of.





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 275/55R20 tires are almost 32" in diameter and more than 11" wide.



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 1500HD. This rear axle was upgraded by Randy's Ring & Pinion in Everett Washington with a new Eaton Posi-traction differential, new 3.42 ring & pinion gears 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 been no 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 in 4-wheel drive at the 1/4-mile track at up to a 130-mph without any sort of problem, even with more than 600 rear-wheel horsepower and 1200 lb-ft of torque.



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


The Duramax Conversion Guide - 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 posted over time and many thousands of miles 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 thread or YouTube video help you with your conversion/swap? Would you like to share this information 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!

www.thedieselpageforums.com/tdpforum/showthread.php?35210
https://youtu.be/--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 to the dealership. Not many of their staff had seen Lil Red before, so it was a fun time with show-n-tell?



Jim

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After driving Lil Red for about a month since replacing the head gaskets, we decided to take it 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.



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.



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 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 (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, which contains complete coverage for this project and several other service procedures.



Read more about Lil Red's Duramax Head Gasket Replacement HERE. If you're not already registered here at The Diesel Page Forums, please do. It's free. Register Now! You may need to register before opening the head gasket replacement link - or post here in this thread. I urge you to do both!

Did this forum thread or YouTube video help you with your conversion/swap? Would you like to share this information 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!

www.thedieselpageforums.com/tdpforum/showthread.php?35210
https://youtu.be/--9bY1T3XoQ

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.

Beyond that, I'll be installing a rubber bed mat soon, 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...

[More Power]

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).



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.



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.



There's no going back... 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 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.



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, 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.



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 and shimmed in the 2" receiver to make it level (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.



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.



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.htm...+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+Lin...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...)

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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...

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



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-...ear-mud-guards

I like the look, and in addition to fitting perfectly onto fenders without flairs (like Lil Red), these exact mud flaps are designed to work perfectly on trucks that have the factory fender flairs. My daughter and I installed a set of these flaps on her 1994 6.5TD Chevy Blazer that came from the factory with 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

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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.

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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.

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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.



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.

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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.



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.



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.





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...



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.



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.



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

Did this forum thread or YouTube video help you with your conversion/swap? Would you like to share this information 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!

www.thedieselpageforums.com/tdpforum/showthread.php?35210
https://youtu.be/--9bY1T3XoQ

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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.