Author Topic: CUMMINS Diesel swap  (Read 5752 times)

Offline Mr heavy chevy

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CUMMINS Diesel swap
« on: October 05, 2016, 11:29:17 AM »
Hello!

I have a pristine 1987 short bed 4x4, and I want to do this conversion/ swap to it.

https://www.youtube.com/watch?v=B34LTUqdgHo

Has anyone done this conversion yet?
i will be researching the parts i need and looking for a good engine/doner vehicle over the next year before executing the build.

just wondering how many parts i can get off the shelf for this project and how much will need to be fabricated-custom. In the video you see a lot of custom work for the cross-member and the motor mounts. as well as mounting the radiator and inner-cooler (but that is way simple by comparison)

I am planning on buying an "in-bed toolbox-fuel tank all in one" to deal with deleting the saddle tanks.
i know they make an adapter for the engine to a 700R4 transmission.
other than that, i have no idea what to do with fitment, wiring, turbo etc etc etc LOL

thoughts?



« Last Edit: October 06, 2016, 11:43:37 AM by Mr heavy chevy »

Offline hatzie

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Re: 12 valve Diesel swap
« Reply #1 on: October 05, 2016, 12:19:20 PM »
If the 3/4 ton GM V2500 is exceptionally clean and pristine you may want to buy a 3/4 ton Dodge W200 chassis with an LA 318 or 360 smallblock or a Leaning tower of power (slant 6) rather than chop up your pristine GM.  Don't do this with a Warlock or a Lil Red Express or a 70's Power Wagon either they're getting kinda rare too. 
Remember the old hot rodders adage...  They're only original once...  They're actually climbing in value as long as they're in pristine original condition.

I would not recommend putting a 12valve in a 1/2 ton GM V1500.  3/4 ton is bare minimum.  The 1/2 ton suspension and axles will not put up with the torque and wieght of the Cummins 12v.

I wouldn't use the TH700R4.  You might look into the 4L80E but the 47RE put up with that Cummins engine for 150-200K miles.  The main gotcha is the cable shifter.  Dodge and Ford used Saginaw columns on the earlier trucks I would bet you can mod the Dodge 94-01 xxRE cable shift column to fit your truck.
Use the Dodge LHD Dana 44 with the stock Dodge transfer case.  You'll need to move the spring perches and shock mounts and build custom length driveshafts but that's about it.  The 3/4 ton Dodge & the 3/4 ton GM used the same 8x6.5" bolt circle.
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Offline Mr heavy chevy

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Re: 12 valve Diesel swap
« Reply #2 on: October 05, 2016, 10:57:24 PM »
sounds like a 3.9 liter may be better.

http://www.cumminshub.com/4bt.html

they still weigh about 700-800 lbs though depending on accessories. but it will work better than a big 5.9 liter when it comes to transmission & axles.
i can just swap in some heavy duty off the shelf, or, custom springs for the front.

it may definitely need some good custom motor mounts to isolate the vibration from the frame though

https://www.youtube.com/watch?v=IC3Nf5YkRSI

Offline Irish_Alley

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Re: CUMMINS Diesel swap
« Reply #3 on: October 08, 2016, 08:00:17 AM »
post moved to the "right" area in the cummins swaps lol.

but i have a 5.9 in my 91 crew cab with the 4l80e. things to think about that i wish i really knew before and it has to do with the trans. i would use a compleat dodge donor use and their trans, with gm you have to use the gm adapter (100-1000) and flexplate (100-400)  and you cant use the 700r4 and no good shop will even touch a 700r4 that is supposed to be put behind a cummins. so trans options with gm are th400 but you wont have OD and top speed might be 60 and mpg will blow. you can get the 4l80e to work with the cummins but you will have to put 500 into a TCU then you will also have to buy a new stall convertor to handle the cummins another 700 and the 4l80 should hold up to the cummins if its stock or close to it (like pump adjustment and turbo mods) and thats about it for automatics. manuals are the nv4500 and nv5600, the nv4500 being most popular and you can get them out of gm or dodges BUT with gm you have to have the adapter and a flywheel. which im planning on using the sm465 flexplate and bellhousing matted to the nv4500 then a np205. but theres 2 different np round 205s with gm a short shaft and long ones about 2" the other is about 4" the long one will require a spacer and shifter linkage modification.

if you go with dodges nv4500 you have to use one that came off a cummins or v10 but the v10 (the v8s use a different bolt pattern and different input shafts) will have to have the cummins flexplate. the nv4500 can have a np205 round pattern 32 spline bolted right to the back for the 4x4 versions nv4500 and the cummins nv4500 will have 29 splines output shaft and will require a 29 spline input shaft 205. you can use the dodge autos that came behind the cummins but the earliest versions wont have auto and the 47RE  is the common swap if i can remember right but theres the 47RH. the rh is hydraulically controlled governor pressure and the RE is electronically controlled governor pressure.

theres also the 727 and 46rh but they dont have the lock up convertor. and if you use the dodge donor you will prob save money and it should just be a simple swap. and if i did mine again or build another i will either op for the nv4500 dodge or dodges auto. if i had a good GM trans laying around i would try and mate that to the cummins with gm adapters but if i didnt have a trans or the adapters i would definitely find dodge parts
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Offline Irish_Alley

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Re: CUMMINS Diesel swap
« Reply #4 on: October 08, 2016, 08:13:17 AM »
but back to the frames theres only a tad bit of difference in the Ĺ ton vs ĺ ton. and people have put the 6bt cummins in blazers. which is kind of overkill imo if you dont tow. the 4bt is a easier swap and will work fine in a DD even if you tow its still ok but a bit pricey. you can normally find the 4bt about the same price as the 6bt and sometimes its more due to the 6bt not fitting in many projects. if you wait for a good deal you can but a donor for 1,000 but some people will pay 3000+. if you think about a cummins going for 2k i have about 4000 into my swap and that includes the price for the 91 v3500
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes