Duramax Diesel Conversions

[More Power]

You can also read more about Lil Red here on TDP (http://www.thedieselpage.com/features/project2-16.htm). :)

Jim

[More Power]

In your conversion truck, how did you get the climate controls and radio to work, I know that your conversion guide mentions that it includes information to produce a running and drivable truck. So, are there any manuals or wiring diagrams for those kind of things in the truck? Also what kind of unforeseen problems further down the road have you run into? Any electrical or drive train problems or other little things? Any help is very appreciated thank you-Robert

I installed the complete under dash/inside cab wiring harness, fuse block, and electrical junction blocks matching the engine/trans package. I also installed a matching dash. This allowed me to use the matching audio system, light switch, pushbutton 4WD switch and instrument panel gauge cluster. I retained the original 1989 control panel for the HVAC system by interfacing it with the new harness. This is covered in the Conversion Guide (HVAC system).

No problems with the drivetrain have come up, except that if doing it again, I would install a matching model year steering column, which would simplify the conversion. The Guide shows how to retain the original steering column and get the cruise, turn, horn and wiper system integrated into the new electrical system.

Jim


For this conversion, how much would the approximate cost be? I've read all the articles I can find on the conversion you did with the '89 however I can’t find a build cost. I'm looking to do it to my 1996 and was wondering about an approximate build cost to just get it running and drivable. Thank you -Robert

Assuming you did all the work, the total cost would depend on what you pay for a conversion package. I've heard of packages going for $5k to $12k. Many almost-new low mileage salvage trucks go for somewhere in the $7500 range, but you'd need a salvage license to bid on insurance vehicles. Ebay can also be a good source for engines and parts.

Jim



You mentioned a conversion kit, aside from taking the parts out if a salvage truck what do you mean?
Thank you Robert


I referred to a conversion parts package that was assembled from a salvage truck. A package will contain the complete engine/transmission, all related wiring harnesses, computer modules, fuse blocks, electrical center, intercooler/hoses, radiator, steering column, etc.

There have been a few "packages" sold on eBay. I urge people to buy a complete package or a complete salvage truck. The little bits & pieces can really run the cost up if you have to buy them over the counter.

Jim

[Margo_325]

Im doing conversion on a 1995 Suburban. Donor car is 2001 Silverado. I have the book "Duramax 6600 Conversions&Repower Projects"

My Suburban does not have an HVAC like in the book, I took all the wiring out behind dashboard (I want to keep the old dashboard), that included all heater wiring as well. Do I just have to compare two car wiring diagrams and search for right wires to connect to heater plugs?
I only left the wires, that came out from drivers door and went behind dashboard to passenger door. How did you get your power windows and central locking to work, I didn´t find anything from the book, how to connect them.

Margo, Estonia

[More Power]

Im doing conversion on a 1995 Suburban. Donor car is 2001 Silverado. I have the book "Duramax 6600 Conversions&Repower Projects"

My Suburban does not have an HVAC like in the book, I took all the wiring out behind dashboard (I want to keep the old dashboard), that included all heater wiring as well. Do I just have to compare two car wiring diagrams and search for right wires to connect to heater plugs?
I only left the wires, that came out from drivers door and went behind dashboard to passenger door. How did you get your power windows and central locking to work, I didn´t find anything from the book, how to connect them.

Margo, Estonia

Your complete HVAC system & control panel should work just like mine does, meaning it'll operate as a standalone system. You'll just need to tap into DMax HVAC under-dash wiring for power/ground/AC clutch engage. I recommend using the Dmax HVAC power and lighting circuits so the correct the fuses are being used. The 88-94 diagram in the book can be used as a guide for your 95 system, but you will likely need the 95 wiring diagram to double-check it.

As was mentioned by THEFERMANATOR, the ECM will be looking for the Dmax HVAC controller. I didn't need to delete that function in the ECM using EFI-Live, but it wouldn't hurt.

If you want to maintain 4-wheel ABS, I would transfer the Dmax truck's ABS controller and related hardware to the Suburban.

And by the way, I consider the Dmax instrument panel essential for the best conversion (the gauges are right and you'll have the DIC).

Jim

[Margo_325]

I did put the Dmax instrument panel cluster in a Suburbans dashboard and fabricated a plastic cover around it. Also I did put a Dmax dip switch, that fitted almost perfectly. So for the HVAC I need just to connect 3 wires to make it work correctly (power, ground, A/C Clutch)? Unfortunately, I dont have Suburban wiring diagram, only the Silverados one.

[More Power]

The pickup wiring diagrams should be virtually identical to the Suburbans.

The HVAC package under the dash should have its own wiring harness - that connects to the HVAC control panel and the vehicle's original under-dash harness.

I connected the original 1989 HVAC harness to the new Dmax harness connections for power/ground and Ac clutch engage. Works great.

Jim

[GordonMarks]

Well, 1st off, mine was an OBD II & you guys, fortunately are dealing w/OBD I.
My Opinion:
You need to get the GM FACTORY MANUALS!! It has all of the wiring diagrams.
The A/C..As I recall, youall are on the right track-LOOK AT THE "a/c Request" wire.
The 95-99(2000 for some) A/C wiring is the same. The control head is a computer.
I'm not sure how you can get the 95 dash to work with the 01(DMAX) since all of the inputs(outputs?) are different & changed again several times.
I used the 01(actually 01-03 I think)DMAX dash & it is usable/fitable(if that's a word)
I need to read the posts again.......

[GordonMarks]

OH, the 95-99 A/C system controls are DEFINITELY different! They changed the controls & the dash. The basic system(box) is the same but the control head is alltogether different as is the wiring.
The ducts are better too. The air flow/cooling(for those down here)is much better on the 95-99's but not as good as the later 2000's +.

[Margo_325]

Thanks, but I already subscribed as a member to alldata myself. Now I got the heater working (need to find the A/C engage wire, but I have some small problems left still. First, how should the coolant circle go through the heater? I have 3 pipe endings coming out from firewall, one I know is A/C pipeline, the other two are for the heater inside.
http://stuff.e30club.org/images/suburban/hoses.JPG
Problably the bigger one is intake hose and smaller outlet? Duramax has two exactly same size hoses, one is coming from the waterpump or near there and the other one is coming from that big hose, that goes to the radiator right side. Correct me, if Im wrong, but then the hot water comes from the lower hose, that goes to the radiator, goes through heater radiator and then goes back to the water pump? Of course, then it gets warm in car, when thermostat valve opens. And also I have A/C hose problems, if someone could explain me the schema, how I can fit them so my A/C fluid circle will be right. If someone can explain me, how I should fit those hoses, I´d be very grateful.

Edited:
Still one more little problem: I have that kind of wiper plug, that does not fit to the suburbans wiper motor, and it has 6 wires, but suburban has only 5, so any ideas? The Duramax wiper motor is different and cannot be mounted on the suburban body.
Picture of my plug:
http://stuff.e30club.org/images/suburban/wiperplug.JPG

[More Power]

Thanks, but I already subscribed as a member to alldata myself. Now I got the heater working (need to find the A/C engage wire, but I have some small problems left still. First, how should the coolant circle go through the heater? I have 3 pipe endings coming out from firewall, one I know is A/C pipeline, the other two are for the heater inside.
http://stuff.e30club.org/images/suburban/hoses.JPG
Problably the bigger one is intake hose and smaller outlet? Duramax has two exactly same size hoses, one is coming from the waterpump or near there and the other one is coming from that big hose, that goes to the radiator right side. Correct me, if Im wrong, but then the hot water comes from the lower hose, that goes to the radiator, goes through heater radiator and then goes back to the water pump? Of course, then it gets warm in car, when thermostat valve opens. And also I have A/C hose problems, if someone could explain me the schema, how I can fit them so my A/C fluid circle will be right. If someone can explain me, how I should fit those hoses, I´d be very grateful.

Edited:
Still one more little problem: I have that kind of wiper plug, that does not fit to the suburbans wiper motor, and it has 6 wires, but suburban has only 5, so any ideas? The Duramax wiper motor is different and cannot be mounted on the suburban body.
Picture of my plug:
http://stuff.e30club.org/images/suburban/wiperplug.JPG

In my 1989 Duramax conversion (http://www.thedieselpage.com/features/project2-16.htm), the heater pipe closest to the engine on the truck's firewall connects to the upper heater supply hose coming from the Duramax engine. I bought a new silicone hose made for a 6.5 engined truck to sweep up and connect to the Duramax heater hose supply line.

Wipers... I used a new complete in-cab wiring harness, and I maintained the original steering column. Using the 2001 harness wires used for the wipers, I made the connections between the wiper control stalk and the wiper motor (using the original electrical connector) using the 1993 wiring diagram. If your vehicle is newer and you're using the original steering column, use the matching wiring diagram to know what function each wiring connection is supposed to operate.

Are you using the original steering column or a column matching your engine package (which is what I recommend for an easier install)?

Jim

[Margo_325]

To Jim: I´m using a Duramax steering column as well. Theres minor problems fitting it, because the lower bracket does not fit and needs to be welded to another place. Same with the shifting cable bracket on the steering column, because Im using my original Suburban shifting cable (it is tight)

To THEFERMANATOR: Could you explain it to me (a simple schema or something), because I have zero knowledges about relays. I know, that I have one wire, what turns on the light in the A/C button, if I give there "+" from battery.

[THEFERMANATOR]

The A/C control head in the 95-99 SUB's output's a 12V+ signal to the A/C system to request the compressor to come on. The 01 DMAX uses a ground signal from the controller to the ECM to trigger the A/C. So you would need to use a relay that is turned on by the 95 control head that would ground the A/C request signal to the ECM. And the A/C light in the control head is turned on by a controller inside of the A/C control head itself. Also the power for the blower motor in the HVAC comes through the origanal underhood harness that ran behind the engine and came down underneath the old coolant bottle. This is the same harness that origanally had all of the ECM wiring in it.

[Margo_325]

Ok, I think I try to do so. Another sad surprise came up. I connected all wires, that is needed to run the engine, so I can start wiring power windows, electric seats etc. I turned the ignition on and only this yellow "Check engine" and glow plug lights came to life. As I don't have any oil in the engine, I didn't try to start it yet, just tried, if starter works and it did. Of course, I don't have a key, the lock cylinder is taken out and I have a big screwdriver as a key, but still, I suppose, Passlock will not disable any lights like battery or oil in dashboard? No gauges were working either. Its weird, because I haven't done any wiring myself, besides these red wires on the picture (they fit anywhere, so I did just put them somewhere)

And also thereare 2 plugs left over under hood:
(comes out from that red box)

and two ones under dash: (yellow one seems to be like airbag plug, but that already connected on the steering column)

Any ideas, where I should start tomorrow?:rolleyes:

[More Power]

No gauges were working either.

Several of the gauges are operated by the vehicle ECM via digital data - not directly by engine sensors. So, the ECM has to be installed for all of the gauges to work as they should.

I would expect some modification of the steering column mounts would need to be done to get the newer style column installed. That is all pretty basic, and having the new correct column would make the overall installation a lot simpler. Personally, I'd get the correct Allison shift cable, and not try to reuse the original Suburban shift cable.

If someone else started the electrical/electronic installation, and didn't document everything, you're in for some late nights tracing wires and figuring out what was done. In my conversion, I documented everything, and kept detailed records, both to help me in the future if I need to troubleshoot a problem and to help any future owner should I sell this truck.

One aspect of the conversion I kept firmly in mind during the process was to keep the conversion as "factory" as possible. Any deviations from this are thoroughly documented (like the HVAC, wipers, etc). This would allow a GM dealer technician to troubleshoot this D/A conversion just like he would a stock 2001/2002 D/A truck. Nearly all circuits, fuse blocks, individual fuses, harnesses and all electrical layout are almost exactly as they are in the 2001/2002 trucks. The conversion guide (http://www.thedieselpage.com/duramaxconversions.htm) was written from that perspective. One reason for doing this was because no one else had completed a GM truck conversion at that point in time (in 2003/2004). If I needed help from the local GM dealer, I wanted them to be able to use their routine troubleshooting resources to help. I knew that custom wiring, custom ECM/TCM, mismatched wiring and mismatched circuits would make it nearly impossible for another person to help. And lastly, I wanted this conversion to look as neat and professional as possible.

Jim

[Margo_325]

Ok, after hours searching, I managed to get my instrument clusters working. It was some grounds, that werent connected. Of course, now it works when ever wants, so some more problems to search for. Now I´m stuck again, because of the fuel pump. I have the suburbans fuel pump, but no duramax one. Where should it be located? I checked the fuel tank, but there was only the level indicator and in the tank there were going only 2 wires (purple and black, probably for level indicator). I have alldata opened, and it shows, that both cars have same colour fuel pump wires (grey and black), but I cant find any available connector in my duramax harness. I used all duramax harness (C3 and C4) under my car. Of course, one opportunity is to make new harness, going from fuel pump relay to the fuel pump, but why to invent something, that should already be there? The alldata shows this diagram:
http://stuff.e30club.org/images/suburban/fuel_control.gif

Also a quick question, how the tail lights should work? There is going 4 wires in, but theres 3 bulbs, each with two strands (or how it is called in english). I sorted out the right wires from Duramax harness, but now idea, how to connect them with suburban lights.

[ToddMeister]

Margo,

The duramax does not use a fuel pump in the tank, the CP3 pulls fuel itself from the tank thru the fuel filter and up to the pump.

Some folks add lift pumps on the frame rail to help the CP3 get more fuel. They will run the pump thru an oil pressure switch so the fuel pump turns off when the engine is not running.

[Margo_325]

Okay, now I just connected the fuel lines, but as suburban has smaller pipe coming out from fuel tank, does it affect the engine work? Today I filled engine with oil and tried to start it with my "screwdriver key" and it actually started for a second. Of course, Passlock then interrupted. What I noticed, that if I turn ignition on, then on the info panel in the dashboard, it says: "Driver 1 - Odometer: 116000 - Low Fuel, Service 4WD, and then it stays at odometer (you can change by hourmeter, business and so on from the button there). But in the book, I saw, that Jim had all gears marked up there (P, R, N, D, 3, 2, 1), if the ignition was on. Well, Jim had little bit different instrument panel as well, but I still think, that it should show it. I got the tail lights working after some hours (in Europe you have to have amber indicator lights, so thats way I was confused).

PS! My headlights are acting weird. When I turn the ignition on, then theres low beam, if I change to high beam, the low beam goes off, actually they both should be on...

[Margo_325]

Now I started connecting inside wires and bad thing is, that my junction block does not match with Jim´s one and if I checked the ALLDATA, then that one there didnt match with mine nor Jim´s.
http://stuff.e30club.org/images/suburban/juncblock.JPG
So I just have to pull out all fuses and put them in one-by-one to see, where I need to connect the right wire or someone has a better solution?

[More Power]

I bought the full set of GM manuals and the separate electrical diagram book for the model year of the engine package I used. In these books was an illustration and pinout descriptions for the junction block I used. If buying the books isn't a possibility, I'd visit a a local dealership and try to get a printout from them for your junction block.

By the way, the separate electrical diagram book isn't strictly necessary because the individual diagrams can be found scattered throughout the service manual book set. Being scattered makes it more time consuming to get all of the information, so I found it better to have all of the diagrams in one book. I recommend getting the GM electrical diagram book matching the model year of your engine package.

By the way, please don't post scans of diagrams or other copyrighted material from AllData or any other source.

Jim

[Margo_325]

As Im building a car in Norway, then in this country, it isnt possible to buy this book, they just dont sell it. Although I purchased all possible versions in alldata, that my donor car could be. It turned out, its a 2003 year model. I noticed, that every year has its own junction block under the dashboard, so now its pretty easy to find out everything. And it was true, that it needs a feeding pump, because before there was problems with starting the car. If it started, then it ran just well. After intsalling a Holley performance feeding pump, it starts just nicely and runs like a sportscar:D

But does anyone know, what to do with the brake fluid level indicator? As my suburban tank does not have such plug, then i just leave it there hanging? Actually I dont like the light in the dashboard, that says, you have too little brake fluid. And as handbrake uses the same light, I just cant disable it.

[DmaxMaverick]

The brake fluid level indicator sensor is a normally open circuit, closed when the fluid level is sufficient. You should be able to shunt the connector to get the lamp to go out. If you do this and the lamp stays on, then you have another sensor or switch in the system that's not happy, or missing, or the brake fluid level harness is not wired correctly into the system. The EBCM (Electronic Brake Control Module) receives the input from the brake fluid level switch, and controls the IP lamp. If you pacify all the switches/sensors, and still have the lamp on, I'd suspect an issue with the EBCM, or a weak/missing ground in the circuit. If you haven't installed the late model EBCM, that could very well be the problem, with the BCM missing the input, or the input is not correct from the park brake switch (which is monitored by the BCM)

[HH]

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 our project was in the planning stages, and while actually working through the conversion, I created many lists that I used to help keep me focused. Here's one of those lists (yes, I kept them all).

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

Jim

This is excellent advice. I have done this and it makes me more focused and also helps me plan ahead so I have the parts I need when I have the time to do the work.

[GordonMarks]

I should have mentioned that during my conversion Jim's book was priceless!! I had no one else to discuss the conversion with since not too many had tried it at that time. I used his mount patterns with some minor mods(which I forwarded to JIM) for the 2WD since I didn't have the transfer case to contend with like he and Ferman did. Mine could sit lower in the frame.
As I mentioned, I'd be glad to talk to anyone about the conversion-my contact info is in the other emails.

[More Power]

I've added several links to Duramax Diesel Power Project (https://www.thedieselpage.com/features/project2-16.htm) page, that discuss the rear disc brake conversion and include more details about the truck's interior. Also, we've begun offering professionally produced motor mounts that greatly simplify a conversion. See the mounts here (https://www.thedieselpage.com/conversionmounts.htm). Jim

[More Power]

A new article is now available online about a 1998 Chevy K1500 LBZ...

https://www.thedieselpage.com/duramax/1998LBZ.htm

[arveetek]

A new article is now available online about a 1998 Chevy K1500 LBZ...

https://www.thedieselpage.com/duramax/1998LBZ.htm


Very nice!!

Casey

[More Power]

Very nice!!

Casey

Blake is really nice guy. I hope we do get together at some point. I heard from him a few days ago, and he said he's still "living the dream". :)
Jim

[TheCanadianGoose]

Hello everyone
I'm currently building a truck it's a 1998 Chevrolet K3500 crew cab dually, it has the 6.5/4l80e combo which is ready to pull. I'm going with a 03 LB7 and allison trans. I currently have the harness getting reworked by Ken Wolkens for a stand alone and have the ECM and TCM already reflashed. Now the questions I have is what is all needed to integrate the LB7 to work with the GMT400 platform? I was told the starter relay will not work along with the gauges, what is all reguired to get the HVAC system working with the 98 hvac and the lb7? and what other problems will I have to figure out? thanks

[More Power]

I received this email this morning, asking about an '80s square body conversion. Thought the discussion might be of value here.


On 2021-04-15:
> I am considering doing a Duramax/Allison swap in my 1984 chev c70
> rollback it currently has a 427 5 speed,
>
> In has a cable driven speedometer I wondering what you have done to
> correct that ?
>
> Also does the Allison have the required hardware internally to drive a
> PTO , I know it has a cover plate but what about the internal gear
> required to drive the PTO
>
> If I do proceed with this project I will be purchasing you guide. Do
> you need to buy a wiring harness to make the conversion or does the
> guide show you how to modify the existing harness.
>
> Thanks In Advance
>
> Larry
>
>


Hi Larry,

I recommend you modify the dash of your 1984 truck to accept the new instrument panel. This will solve the speedometer problem and you'll gain a lot of functionality with the new powertrain. I also recommend you install the steering column that matches your engine package. This'll make it easier to shift the Allison, and it'll add a lot of functionality as well.

I know the early Allisons were setup to run a Power Take-Off, but I know the PTO was dropped a few years into production... before re-adding PTO in more recent models. So, to answer you, I don't know. I guess it sort of depends on model year, but I don't have a model year breakdown for the PTO.

For wiring harnesses, I recommend using the OE harness that matches/came with your engine package. New, these factory harnesses are about $600/ea (one for the engine and one for the Allison). One of the more expensive options is to acquire an aftermarket stripped-down harness that was designed for boats/RVs/basic conversions, but they require a specially programmed ECM/TCM and you'll lose most/all of the luxury features that came with GM's 2500/3500 trucks. Contact ppepower.com or bankspower.com for more info about their harnesses and ECM/TCM. Just remember that using an OE harness doesn't force you to use the extra features - you can pick and choose. The Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm) we offer shows you how to install the OE harnesses, which is the least expensive option - no cost if it came with your engine/trans.

In the meantime, I'd suggest you spend some time with the following article that shows a 1987 Chevy C30 conversion...

https://www.thedieselpage.com/features/ClarkDMConversion.htm

Good luck,

Jim

[More Power]

On 2021-04-27, mj m wrote:
Good morning! I have a few questions about the Duramax Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm)....

I wanted to know if there were instructions for how to modify dash components in a truck prior to 1995... I know that you did this in your 1989 truck but was curious if the instructions are included in the guide.... Second, does the Guide specify which intercooler to use.... and the last question, are the engine mounts still available for purchase?

Hello,

Yes to all questions.

I recommend modifying your original dash to accept the instrument panel from the truck matching your engine package. I did not go that route, but many others have. It'll require fabricating a "surround" that blends your original dash into the new instrument panel. Generally, a custom automotive audio installation shop would have someone with the skills necessary to do a great job - sorta like fitting custom speakers into a vehicle that didn't have them.

That said, the Conversion Guide does show how I installed a complete new dash into my 1989 Chevy. It's a big job... If you go that route, I'd install the new truck's HVAC package and venting system along with the cross-cab aluminum underdash support. That way you'll be able to use the new truck's HVAC (heating, venting, air conditioning) dash control panel and the system's climate control... and it'll make for an easier installation. I also recommend using the new truck's steering column - for Allison shift function and electronics - plug n play. You'll just need to relocate the firewall mount bracket on the new steering column.

I used a Dodge diesel pickup intercooler, but others have used a Duramax intercooler... I used a Dodge part because that's what I had access to in 2003. The Guide shows how to modify the intercooler and how to install it. An intercooler is essential for a performance truck or one that will be used to tow heavy. For a light-duty easy driven truck, the intercooler is more optional. I know of some who didn't install an intercooler and their truck did just fine.

The motor mounts are still available.

Thanks,
Jim

[More Power]

Recently, I've received a couple of requests for more information concerning a Duramax/Allison conversion in the 1990s 2 Wheel Drive (GMT400) body style trucks, asking whether the motor/engine mounts we offer would work. The answer is YES, but the transmission mount crossmember would need to be modified. Member Gordon Marks kindly sent me a couple images of his modified transmission crossmember, which explain how he accomplished his installation. Thanks Gordon!

Note: The factory 4WD GMT-400 (1990s) transmission crossmember works perfectly without modification in 4WD trucks. It appears the 2wd TRUCKS/SUVs have a somewhat different frame rail dimension when compared to the 4WD models. Mock-up the installation before committing to welding on the added material. You may find you need to adjust the height up/down a little to get ~ 3/4" clearance between the rear of the transmission and the transmission tunnel.

You can see from these photos that Gordon flipped the modified 2WD crossmember upside down and mounted it below the frame rails. Be sure to use lock-washers and thread locking compound just to be sure. Jim

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=5929&d=1621261395
https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=5930&d=1621261446

[More Power]

I received this message and photo from Patrick yesterday. You can expect to see his truck on the road somewhere in Massachusetts before long!

Jim



From: PatrickS
Subject: The Diesel Page - Duramax Conversion Mounts
Date: Mon, 24 May 2021
To: The Diesel Page
Jim,

The mounts arrived today and I was impressed with the quality of the parts. After work I bolted them up and, while an involved process, I got the drivetrain in. The mounts were worth every penny.

Patrick

2000 K2500, CrewCab Shortbox

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=5937&d=1621961440

[DayRadebaugh]

I have a low mileage '99 Suburban with a 6.5. I saw the discussion of the conversion to Duramax, but it said it was intended for only the '88-'98 models. Am I correct in thinking that the difference would be in the dash-instrument cluster only?

Thanks

[DmaxMaverick]

It depends on the body style you have, GMT-400 or GMT-800. 1999 was a transition year, and I don't recall how the Suburbans were released, if they were a half-year release, or if there was a difference between the weight classes. 2001 was the first model year for the Duramax. GM has always found a way to defy any direction of logic during these times. A GMT-800 (1999+) would be the simplest, with very little accommodations to consider.

[DayRadebaugh]

It depends on the body style you have, GMT-400 or GMT-800. 1999 was a transition year, and I don't recall how the Suburbans were released, if they were a half-year release, or if there was a difference between the weight classes. 2001 was the first model year for the Duramax. GM has always found a way to defy any direction of logic during these times. A GMT-800 (1999+) would be the simplest, with very little accommodations to consider.

Thank you. Would you happen to know how I can tell the difference? From what little reading I've done, I'm guessing mine is a GMT 410.

[DmaxMaverick]

I suppose I was asking the question. Which do you have? I simply don't recall what GM did during that transition, and I don't know what the equipment and RPO stickers should show to determine it. As sure as the sun rises, when you have it all figured out, an odd duck will show up. If yours looks like previous 1990's models, then it's a 400. If it looks like more modern models up to 2006, then it's an 800. It's important to the simplicity because a later model will fit the instruments and harnesses you'll need, rather than shoehorning everything. Look at the panoramic picture at the top of this page. Which grill looks like yours? The trucks on the far left and right are GMT-800 trucks, with different models mixed in between. Lil' Red is a GMT-400.

[More Power]

Hello everyone
I'm currently building a truck it's a 1998 Chevrolet K3500 crew cab dually, it has the 6.5/4l80e combo which is ready to pull. I'm going with a 03 LB7 and allison trans. I currently have the harness getting reworked by Ken Wolkens for a stand alone and have the ECM and TCM already reflashed. Now the questions I have is what is all needed to integrate the LB7 to work with the GMT400 platform? I was told the starter relay will not work along with the gauges, what is all reguired to get the HVAC system working with the 98 hvac and the lb7? and what other problems will I have to figure out? thanks


Many questions....

First, there's no need to have the Duramax underhood/in-cab harnesses reworked. With the exception of splicing in the HVAC controller/package wiring into the Duramax in-cab harness, the rest of the original in-cab/underhood electrical will be stripped out and replaced with the Duramax harnesses, fuse panels and electrical centers. This actually makes it all a lot easier. Trying to jury-rig an old/new composite electrical system adds so much complication to the conversion that it discourages most who attempt it.

The ideal is to create an electrical system that looks and functions like the factory Duramax system. The truck will be worth more at the end and it'll be easier to troubleshoot if a problem does appear.

Here's a story about a 1998 Chevy LBZ conversion (https://www.thedieselpage.com/duramax/1998LBZ.htm) that used our motor mounts (https://www.thedieselpage.com/conversionmounts.htm) and Conversion Guide

This Thread (https://www.thedieselpageforums.com/tdpforum/showthread.php?35210-Lil-Red) has answers for some of your questions.

Our Duramax Conversion Guide (https://www.thedieselpage.com/duramaxconversions.htm) has answers for most questions.

[More Power]

I received this message and photo from Patrick yesterday. You can expect to see his truck on the road somewhere in Massachusetts before long!

Jim



From: PatrickS
Subject: The Diesel Page - Duramax Conversion Mounts
Date: Mon, 24 May 2021
To: The Diesel Page
Jim,

The mounts arrived today and I was impressed with the quality of the parts. After work I bolted them up and, while an involved process, I got the drivetrain in. The mounts were worth every penny.

Patrick

2000 K2500, CrewCab Shortbox

https://www.thedieselpageforums.com/tdpforum/attachment.php?attachmentid=5937&d=1621961440

This above message was posted in may of 2021... just about 2 years ago. I received an update from Patrick a few days ago, along with an order for another set of our conversion mounts (https://www.thedieselpage.com/conversionmounts.htm). I like his truck's new hood! Here's what Patrick said recently:


These mounts are actually the second set I’ve purchased.

A couple years ago I bought a set to put an LB7 in a 2000 K2500. I chose not to body lift it and instead made a HD hood. Attached is a photo of that truck.

I’ll keep you updated on this trucks swap.

https://www.thedieselpage.com/images/Patrick-Sundby-sm.jpg