I need to know what i would need besides a cummins and a new transmission to make my trusck a diesel. I plan on using a 12 valve from the same year truck as mine to simplify it. Would the transmission and axle need to beswapedand if not what would i need to use? The axle is a 3.5:1 8.25 and the tranny is a 4-spd auto.

 

I predict that you'll blow up both the tranny and the rear axle. You'll need the entire fuel system too. Get a donor truck and do the swap, it'll be easier.

oh, and I'm guessing you've got a 1/2 ton? You're going to scrape frame up front. That cummins will weigh over twice as much as the 318.

 

yeah it's a half ton, i thought about a hole donor truck. there is one for sale in my town. it's a 87 3/4 ton withth cummins but it's 4 wheel drive. Can i get the axle out and not usse the front?

 

The other issue you're going to have is that your frame isn't as strong as a 3/4 ton, and it may need to be reinforced to keep from buckling under the weight. A 318 block is what, 300 pounds? The cummins block is over 1000 pounds.

You could swap the rear axle, you may need shims to get the pinion angle correct.

What's wrong with the donor truck? If it's sheet metal it might be better to just swap your cab/bed onto the w250 frame and inherit the 4wd.

 

The 87' is a piece of junk, I would consider the frame to be unusable from the bed back. the engine is about the only thing i interseted in, In fact I might just bye it the tranny, and the rear axle. I thought the frame were the same for all 1/2 ton to 1ton trucks? Atleast in the front.

 

Grab your tape measure and check it out. I don't know for sure, but it would make sense that the heavier duty trucks would have heavier duty frames. Save cost and weight on lighter duty trucks.

 

just from vehicle experience, Id say youd be better off sellin your truck and buyin a cummins power dodge. no more head ache of swappin. worryin bout proper mounts, etc. besides, youll need any computer or wire harness for the cummins. they are different from a gasser truck. (40% less parts )

 

yeah the cummina 12 valve has no electronics thats why I was thnking about it. I casn't really sell my truck, it's too nice and too luxurious. I getting it painted this summer and want to keep it.