CTD01

Ok I got a 1977 suburban K20. I got a 1995 ram 2500 cummins. I also have a nv4500. I want to make my self a cummins suburban. I was just looking for any input on this who has done it and can give me some tips. I can see that the turbo is guna be real close to my evap core. I also would like to see what you guys would run for the rad big gm or big dodge? I aint lookin to make a speed demon I just want a nice dependable truck. Also what rear diff would you guys suggest. I got the stock 10.5 full floater,2 dana 70s one posi one not and a dana 80 posi. The only problem with using the 80 would be finding a gear set for the front since it is 3.54. Any tips are greatly appriciated. Thanks,

Paul

patdaly

Look thru here first, there was a sweet K3500 conversion done, then changed, but done first with the stock GM frame.

https://www.dieseltruckresource.com/...2-t205371.html

Also look at 4BTswaps.com, specifically a 4BT site, but since it is just a 6BT with 2 cyl. lopped off, most info is relevant. They make everything to direct mount this swap.

I am either doing a 4BT into a 95 K3500 or Tahoe/Suburban....... Looking for a Sub right now.

Greguw

I'm doing my 1990 Sub right now ... I got a little carried away , I personally don't believe the stock frame is strong enough to handle the weight of the cummins .
I am in the process of plating at boxing the frame . I order new custom Deaver front springs to handle the weight of the cummins , there 4.5 inches longer in the rear for a better ride , jeff at deaver said these spring will ride better than stock and handle the weight .
There building me a 8" spring that has 12 leafs in the pack .
I have just about everything but time ... I have been doing a hour or 2 a day ... I'm going to run a 1996 cummins 6bt , new version nv4500 dodge HD , NP205 with 1410 yoke and all gone thru .
New in the crate dana 60 / 14 bolt with 4.56 military M1008 axles .
I was in the custom 4x4 business back in the day and have not done a build in over 10yrs ... I have all the skill and knowledge ... its not like it us to be , Its going to be a great truck but lots of work ... I forgot how much .
Heres a pic of my frame frame mocked up and braced with the cummins cross member in place , I'm opting for the stock gm mounts for my build .
I'm around feel free to ask away .
greg

dieselJon

Take it from me. I tried, then junked a project. Do a body swap. Nothing needs to be custom on the drivetrain saving $$$$.

CTD01

Yea but I think it would be cool thing. I got everything I need to do it plus my family has been in the automotive business since 1948. I know it guna be a big job but im up for it. As far as saving money its not a problem money is no object but i want to say I did it myself.

Greguw

Sounds like your going to have a great project ... I was at work on mine today , I was still welding on the frame . You really can't cut corners building a diesel truck .
I would box or plate your frame in the front sections , I posted a few pic of ideas , also plan on replacing all of your rivets in the front section with 7/16 bolts ... I have seen many of these trucks with out a cummins and the rivets come loose over the years ... especially after about 10k with a cummins .

CTD01

Yea your pics look awsome and thank you for the advice.

Twisted Inc.

a/c is going to be a royal pain!, not impossible just a pain, your a/c compressor is going to have major clearance issues with the frame, as well as what you said you already noticed about the evap core, when i did my swap i went with the dodge rad. and intercooler, but you may have more options with the 77 front clip,....1st gen motor mounts are relatively easy to addapt onto the gm frame....as far as rear ends the word on the street is that the gm 14bolt is stronger than the 70 but the 80 is just a little stronger than the 14 bolt, but thats just hear say.........IMHO i would stick with the 14bolt if the gears are high enough for your application....they are very easy to replace and an all around tough axle, if you have any questions just ask! good luck!

CTD01

Ok what motor mounts do you guys suggest? I see some people using chevy some using dodge. Im just afraid of ripping the chevy mounts as I have done on my gmc with a small block. My buddys got a bbc chevy and he put a chain from the head to the frame because th mounts couldnt hold it lol. I aint guna beat on it but a diesels got alot more tq then my sbc and I dont wana keep putting mounts in it.

ahow

i used the chevy mounts when i did mine. im not a fan of the dodge mounts

ILdodge1977

About 7 years ago someone from Finland did a really detailed swap on TDR. If you pay for a membership you should be able to find it. Lots of interesting custom fab work. The guys name was Timo I think.

CTD01

Cool thank you.

Greguw

I am also using the chevy mounts , 6.2 diesel moog mounts .

CTD01

Now I've been thinking. Would I be better off with a 1 or 2 inch body lift for evap core clearance and bell housing clearance?

Twisted Inc.

i dropped the engine crossmember enough to where i could clear the front valve cover with the hood then i bolted the fan on! major oversight! so i added a two inch body lift to solve that problem!......if you do a body lift PLEASE raise your bumpers! its a pain trust me iv done it, but well worth it