Cummins swaps.....Who has done them? Need some advice

[Chevy3+3]

I have been through the build threads and no one seems to ever finish a project or are they are still in progress. I have some simple questions I hope some of you can answer. Someday I would love to do a Cummins swap but don't want to jump in not being prepared or educated.

My truck: 88' Chevy V30 4x4 CC Dually

Current drivetrain: 454, TH400, NP205

My questions:

1. What is the difference in the 1st & 2nd Gen 12 valve Cummins engines?

2. Which would be a better choice?

3. Which manual transmission would be the easiest to swap in. I would love a Manual tranny but would think a little more work would be required (clutch pedal, clutch master cylinder, etc.).

4. If I were to use an auto tranny what would be my best option with simplicity and dependability in mind.

5. Are body lifts usually required for firewall or tranny clearance (depending on tranny)?

6. Can I utilize my factory radiator support and radiator? Or are mods definatley necessary in this area?

7. Are there any prefab or factory built mounts or crossmembers for these types of conversions?

Thanks to any and info. I just hate going into a project like this halfa## because corners usually tend to get cut at that point. If I decide to tackle this project I want it to fit well and be dependable.

[mattcrp1]

I was in the middle of a 6BT swap into a 79 crew cab, when I was forced to sell due to a job situation. I found a lot of info on 4btswaps.com .I had the motor and transmission in the truck and was working on the fuel system. The early and late 12 valve motors main differences had to do with the injection pump style. Good luck. There was a vendor who sold adapter mounts that worked like a charm.

[881ton]

Tennessee Diesel conversions has the crossmember and motor mounts you need. I used these on my conversion and they are very user friendly. No mods to firewall or frame. My 6bt cummins fits better than the old 454. IIRC most guys use an nv 4500 or nv 5600 manual trans. I had bought a complete donor truck and installed the whole driveline ( a 518 Auto w/overdrive). I used my stock radiator support and put in an intercooler from a second gen (1994) dodge. a little modification was needed. if you can do some welding/fabricating it will help you make things fit. 4BTswaps.com has some invaluable resources, as well as the cumminsforum.com I found it to be a pretty straightforward swap. Good Luck, Rob.

[Chevy3+3]

Thanks for the replies. I will definately check out the websites.

[brimc]

First off have you checked the "General Truck Forums > Engine & Drivetrain Diesel Conversions" section yet?
You have a great starter truck there. I want that exact truck. Been looking for 3 years. Either to much $ or way too far away. What about pictures?
You don't need to buy much if you find yourself a good doner truck. It will have almost everything you need. Basic tools and a welder is most of what you need. If you are not planning to do it yourself, I don't think it would ever be worth it. Read, read, read then ask your questions. Everyone's want / needs are different. You can build it as you want.

[Chevy3+3]

Originally Posted by brimc

First off have you checked the "General Truck Forums > Engine & Drivetrain Diesel Conversions" section yet?
You have a great starter truck there. I want that exact truck. Been looking for 3 years. Either to much $ or way too far away. What about pictures?
You don't need to buy much if you find yourself a good doner truck. It will have almost everything you need. Basic tools and a welder is most of what you need. If you are not planning to do it yourself, I don't think it would ever be worth it. Read, read, read then ask your questions. Everyone's want / needs are different. You can build it as you want.

Here is a pic of the truck you have been trying to find. I figure it is a good starter truck. I "HOPE" next years wheat crop is good to me and my wife okays the Cummins swap. I am really seeking info now so I am better prepared if and when I ever decide to tackle this project. I am very mechanical and know how to weld so it shouldn't be to bad.

[881ton]

I would look for a complete donor truck (dodge cummins) you can reuse a lot of the parts that would be a pita to source or fab. also saves time, plus you may be able to sell some surplus parts to recoup some $$. If you start w/ a dodge cummins it makes it easier b/c you don't have to change the intermediate plate between the engine & bellhousing. If you buy an industrial cummins you will have to do this, ie: engine from ag equipt. or a step van. I bought my donor for $3,000.00 came with a nice fisher plow ( plow alone is worth $1000.00)( engine/ trans & t-case had 42,000 original mi. ) ex parks dept truck frame was rotted bad. When I looked on ebay dodge cummins engine alone was between 2500.00 and 3500.00 with 75k to 150k on them. When you find an engine or donor truck inspect the oil pan well, New nos first gen oil pans are non existent, although you can prob find used. the difference between the first gen (89-93) is the injection pump first gen use a bosch rotartu style, this will limit your output if you are going to get some HP out of it. second gen (94-98?) uses the P-pump design, there is more Hp to be gained w/ a p-pump. I wasn't looking for all out perf. just reliability. regardless which way you go, the intercooler from a second gen fits well with a little modification, the fist gen I/C is very small compared to second gen. DEFINITELY DO THE KDP TAB search the killer dowel pin on cummins forum. I hope this helps you out.

[Tutt]

i finished one about a year ago.

im not real good at taking pics, but here is a link to what i did take.
http://s513.photobucket.com/user/jos.../library/Dooly

it was a ton of work....but very worth it.

i answered what i can below...

Originally Posted by

1. What is the difference in the 1st & 2nd Gen 12 valve Cummins engines?

[COLOR="green"

on the engine itself, the injection pump is the biggest difference[/COLOR]

2. Which would be a better choice?
2nd gen (p-pump) makes more power. 1st gens are said to get better mileage. the mileage is probably debatable. there is no doubt that a p-pump will make power easier. the radiator and intercooler from a 1st gen will swap over easy (what i used). i think the 2nd gen stuff is wider and may not fit as easy.

3. Which manual transmission would be the easiest to swap in. I would love a Manual tranny but would think a little more work would be required (clutch pedal, clutch master cylinder, etc.).

4. If I were to use an auto tranny what would be my best option with simplicity and dependability in mind.
47rh is the go-to. they came in 94-95. the are hydraulically controlled except for OD and lock up. i am controlling them with switches right now. up thru 93 they did not have a lock up converter. 96 and on is electronically controlled.

5. Are body lifts usually required for firewall or tranny clearance (depending on tranny)?
no with a 47rh. it is tight though. my truck is 2wd and lowered. manual trans might require a bolt in hump.

6. Can I utilize my factory radiator support and radiator? Or are mods definatley necessary in this area?
i used the 1st gen dodge radiator. i wanted to use stock hoses and use the radiator that was designed for the engine. the 1st gen radiator is very easy to mount and fits really well. i also used the 1st gen intercooler. this required some modification to the core support, but it wasn't too bad. people have used many many different radiator and intercooler combos.

7. Are there any prefab or factory built mounts or crossmembers for these types of conversions?
tn diesel conversions makes some mounts, but they are pretty expensive for what they are. i basically copied them. your situation is a little different with the 4x4.