I just bought a used,clean 01 GMC 2500HD crew cab,its got the 8100 big block/allison 1000 trans.I am going to drive it as is its got 76K on it,the 8100 is strong,but it is no Cummins.Any help with this would be appreciated,I hope to do the swap next summer,I want to keep this as simple as possible,and use the existing allison trans,and probably an ISB or ISBe.Im not looking to make a hot rod,I already have that(my Dodge is quick enough).I want a reliable,strong tow vehicle,probably around 350-400RWHP.

 

There is a guy that has asked a few times about swaping a blown D-Max for a Cummins, and there really hasn't been anyone that was able to help... I know it could be done, anything is possible, but you may be the first. There would definately be a lot of fab work, and maybe a body lift for underhood clearence (like Mad Dog's Ford)

 

You might go over and ask some of these guys for some info.

http://www.cummins-conversion.com/photos/index.php


Hope that helps!

 

www.fordcummins.com was suppose to be making a website a while ago called www.chevycummins.com

 

Thank you guys, I ve been looking only a few days so far.I doubt Id need a body lift since the HD GM'S already have a body lift from the factory of 2" to clear the allison.Ive only had this truck 5 day,and so far I really like the GMC,its a very nice driving truck,the stock powertrain would proably make most ppl happy,but after pulling with my twin turbod truck that makes 400 with the box off,it just feels very weak .The 8100 is strong,but burns gas to the tune of 11mpg,so the Cummins would be a big help there too.I really love this crew cab,as compared to my quad cab Dodge,and a Cummins would make it a unique truck.

 

Ive been trying to register on the cummisn conversion site all day,and I keep getting a general error message,and a statement that says die robot.

 

Personally, here's my take on it, I am sure others will disagree. It seems that a modern, electronics-filled truck such as your '01 GM are sort of pointless to swap engines in. Or at least, if you really have to have a diesel, buy a D-max, live with it for a while, (they are quite nice units too) and if you decide to, swap that one for a Cummins.

My reasons for this are several. One, engines are headed back - into the cab are, that is. This makes packaging a long unit such as a 5.9 I-6 aa real challenge. One (of many) reasons OEM's are desiging trucks this way is the LARGE number of people using trucks as thier normal mode of transport now, and the need for improved crash safety. The space they need is what they are searching for, and it requires that big engine to move back some.

Also, with as much as these truck coast, converting a gas rig over to a diesel after the fact makes the $5555 CTD option in the Dodge seem cheap. You'll need to swap the tank, all associated fueling components, the wiring harnesses, possibly even some suspension parts as the CTD weighs more than an 8.1L. This is just a start.

It sounds like a neat project, but wouldn't you be dollars ahead just going and buying a newer Dodge/Cummins?

 

He probably would be except for one thing......its's a Dodge. Therein lies my problem. In my humble opinion a Chevy truck with a Cummins would be the ultimate package. I know it has been said before and so on etc.... but Honestly I have had all three major brands including two Powerstrokes, two Cummins, and multiple Chevys and my trucks work for a living day in and day out and I have not found one that will hold up to hard off road farm use and such as well as the Chevy. Now I haven't had a Chevy diesel because I did not like their old diesels but have had lots of luck outta the old 350 (including one that went 275k with just a water pump and fuel pump needing replaced) but I needed more GN pulling capability, hence the Cummins wrapped in a junk truck. Just look at the front ends of these things, the 60 is a good axle but the wheel bearings and hubs just dont cut it.


Just my $.02

Tom

 

It is a 4x4? If so id to a live axle swap for sure. Never trust IFS unless it on an H1.

 

First off,thank you for all the advice,and help.I already have a Dodge,and my total budget for this project truck included is around 21K,so i plan to sell off the 8100,when done.If any of you know whre I could find a used mega cab 4x4 within my budget,let me know.As far as a duramax,I dont want one with hi miles,and any of them that were in my budget had 190,000 miles on them.Id take a 250K miles cummins over a 100K dmax engine any day.I know the Cummins engine inside and out,Ive got a spare engine here,many parts,and such,this is the engine I want to use.Ive got a good foundation now,and Id like to use an engine as new as the truck in case down the road,emissions are checked on it,it will not pass with an older 12V engine.Finally after owning 2 Dodges,and about 5 Gm trucks,I think the GM's hold up better as far as the body goes.Please dont try to the IFS is weak thing with me,ive got a 16yr old 1500 GMC excab plowing with an 8'6" Western V plow that weighs over 900 lbs 5 yrs now,and it had a 7'6" for 6 yrs before that,and everything still works fine,nothings broken,just normal wear,idler arm/pitman arm replaced.Overall the GM IFS truck ive owned have had no more front end wear or problems than my Dodges.Im going to start off by getting the wiring diagram for my truck,and see what I've got to intergrate to do this swap,if it isnt feasable,Ill save my money and wait until someone builds what I want in a truck.To me the GM/Cummins is the best of both worlds.

 

The Gm HD's use the same front end IFS,whether it is 2wd or 4WD,its the same parts,and they sit the same height.What is not to trust on the IFS?Other than the tie rod sleeves,which only seem to bend when highly modding the engine,and abusing the truck,something i never plan to do with it.The only other thing ive seen is the CV joints explode,but every time it is when someones lifted the truck the wrong way,cranking the bars,and or using new keys.My cousins Dmax has a 6" lift,and 35" Nittos,and he sled pulls with a modded engine,he's never had any trouble with the front end,and hes pushing 100K now.From what ive seen,if you keep the truck stock height or lift it the right way,and the joints arent an issue.

 

Look for Brayden, not sure if he is on this site, but he is on TDR and I think thedieselplace. He as done a few allison swaps in cummins trucks. He could at least help you with that.
www.destroked.com This is a powerstroke to cummins conversion site, I know this isn't what you are doing, but I heard that they are working on a cummins conversion wiring harness. If it would work for the gmc it could save a bunch of time.
www.autoworldmt.com A good resource for cummins conversions too. They have done quite a few. Not sure if they have ever done one like yours but I bet they could help even if they haven't.
Good luck. I would love that combo too.

 

i cant say if it will work or not.

All i know, when it comes to making conversions, you will always get negative responses from guys on here. unless they know of a/various conversions that turned out flawlessly!

around here they swap cummins engines into anything, ford, chevy's, big trucks, etc, not sure how they figure it all out! but they do,

i saw a Ram4000 truck that came with a gasser, they swapped it with a 24valve cummins and a old style rotary inj pump...

but dont ask me how your project could be done, I've been thinkin about doing a swap like yours also

 

I planned on contacting Brayden,I was hoping someone had done it,and would share.I know mating the cummins to the 1000 is the easy part,its the wiring of the factory GMC goodies,to the cummins engine and keeping the cruise,air bags,and pcm happy that i will need to look into.There actually looks to be a lot of room in the engine bay,as far as height goes,front to rear looks ok too.