cummins conversion

[laster]

well this idea and project was just thought about a hour ago but im planing on doing a cummins conversion and need help on how to get started and where to begin...info....the truck is a old farm truck 74' chevy k20 with a flat bed, its been in the family for since new, and it hasn't run in 5 years been in barn since motor-i found a guy with a totaled out 03' 3500 im trading my 4-wheeler for but the motor still turns over and runs.......do they make conversion kit or will i have to make one of my own?? i wont to make around 600 rwhp and wont to make this a "sleeper truck" would like to turn a few heads and drop a few jaws at the truck pulls, when and if i can get this project up and running gonna leave the body the way it is, and just clean the spider webs outta the cab, and clean the birds nest off the dash, any info and heads up will be appreciated!

:thankyou2:

 

[Mo Smoke]

are you using the same drivetrain from the 3500 ?

 

[SmokeShow]

I know there are companies that make engine mounts/crossmembers for putting 12 and 24 valve Cummins in the ol square body GM trucks but I don't know if those can be used for putting a Cummins in one or not.

What drivetrain are you thinking of running behind the cummins? IMO you'll want to use a tranmission and transfer case out of a Dodge. With the kind of power you want to make, I'm told the torque you'll be making will likely be more than the ol GM driveline parts (ie. NP205, 14B rear) are up to handling. But then you'll find that the GM front diff. drops on the pass. side whereas the newer Dodge stuff (the older Dodge stuff is pass. side also but again, is basically the same as the ol GM stuff and not up to the task I'm told) is driverside drop. So you'll need to put a Ford front D60 in there if you run the newer drivetrain as it drops on the correct side. The 78-79 Ford D60 I'm told is pretty much a bolt in affair or at least the easiest.


HOWEVER, if you aren't gonna beat on it too hard, the GM stuff should at least last a while and be WAY easier to convert to. Just concerned with the comments you made about sled pulling with it. That's where I think you will find the limits of the older GM driveline behind the torque of these diesels.


Good luck.

 

[TheSh111t]

I know there are companies that make engine mounts/crossmembers for putting 12 and 24 valve Cummins in the ol square body GM trucks but I don't know if those can be used for putting a Cummins in one or not.

What drivetrain are you thinking of running behind the cummins? IMO you'll want to use a tranmission and transfer case out of a Dodge. With the kind of power you want to make, I'm told the torque you'll be making will likely be more than the ol GM driveline parts (ie. NP205, 14B rear) are up to handling. But then you'll find that the GM front diff. drops on the pass. side whereas the newer Dodge stuff (the older Dodge stuff is pass. side also but again, is basically the same as the ol GM stuff and not up to the task I'm told) is driverside drop. So you'll need to put a Ford front D60 in there if you run the newer drivetrain as it drops on the correct side. The 78-79 Ford D60 I'm told is pretty much a bolt in affair or at least the easiest.


HOWEVER, if you aren't gonna beat on it too hard, the GM stuff should at least last a while and be WAY easier to convert to. Just concerned with the comments you made about sled pulling with it. That's where I think you will find the limits of the older GM driveline behind the torque of these diesels.


Good luck.

I am in the middle of doing a Cummins swap into my 1981 Chevy 2wd short bed (Same boddy style as yours, just newer front clip). I did quite a bit of research both online and at 2 local 4x4 shops. I can not comment on the 4wd aspect of it, simply because I have a 2wd truck therefor did not research that part of the swap, but I can comment on the strength of the GM 14 bolt rear diff. There are 2 differant 14 bolt rear diffs. There is the full floating unit (10.5" ring gear) and semi floating (9.5" ring gear) The full floaing 14 bolt is very strong. At least equal in strength to a Dana 70 and by some accounts a little stronger. I can't tell you how hard it is going to be to convert all the 4wd parts, but as far as the rear diff, is quite strong. Not trying to start a debate, just didn't want the 14b to get a bad rep. Good luck with you build, keep us updated.

 

[laster]

thanks yea my truck has the floating 10.5 rear, and WOW its gonna be a pain to do all this by myself with nothing but a cherry picker!! mostly the 4x4 parts! but i got the to trucks beside each other...just waiting for the motivation

 

[hyper14h]

well if you have a dana 44 in the front you can go to an army surplus and get a dana 60 out of a chevy they have them all over the place there most never used and there a dime a dozzen and it will bolt right in the only prob is there going to come with 4.56 gears in them as for the 205 transfercase i would run it and see what happens ive alwas heard they were the onlything stronger than an atlas. might be true might not be but i wouldnt be afraid to give it a shot.