i have a 84 4 wheel drive short bed and a 92 3/4 ton 4 wd 5 speed that the body is pretty well trashed on. I was wondering if the frame would be strong enough on the half ton to put the cummins in. I will be pulling a trailer with it, put I guess you could box the frame. if anyone has done this give me some info on how hard this would be.

 

It sounds like your talking about a similar swap to what I did. My truck is an '88 W100 long bed. We found a 92 W250 with no title, and swapped the entire diesel drivetrain into my truck including every last piece of wire. Being thorough will be your best bet at getting it right. I even swapped the dash to get all of the correct lights and message center with "wait to start" message. It went pretty smoothly, there were some bugs to work out, and it did take some work to the core support to get the intercooler in, but no one can tell it didn't come as a diesel truck. As for the frame I have the same concern for mine. Sled pulling is pretty much out of the question for me anyway. As for boxing the frame, its a good idea but keep in mind you have to do the whole thing not just parts of it as it can stress weaker/stinger areas. I read somewhere that the older truck frames like ours were the same as the 250 frames but I've never measured one to see so I can't back that up. One thing is for sure, you'll have an extremely lightweight diesel truck if you follow through. I am completely happy with how mine turned out.

 

Ok that is what I'm wanting to do, did you put the 8 lug rear end and leaf springs or did you use the half ton. Also was changing the dash very hard?

 

The dash wasn't hard really, it was just very trying on patience. It took several days of quiet to get right. I did put the D60/70 8 lug axles in the truck, the swap was relatively simple icluding the steering that bolted right up using the stock 1/2 ton drag link. I used the donor truck front springs for a while, but I just replaced them with a set of Skyjacker leveling springs. I replace the rear springs with a set of nasty one ton springs that came out of a first Gen with a mechanics body on the back. The springs were the same length and width, and bolted right up to the 1/2 ton mounts and shackles.

 

so the stock shackles and mounts would be strong enough if i pulled a goose neck tailer or would it be best to switch them? did you change the fuel tank, and if so would the diesel fuel tank fit within the same location on the short bed?

 

There was no difference between the 1/2 and 3/4 ton spring mounts/shackles so there would be no strength issue. Honestly there was almost no difference between the two chassis'. As for the fuel tank the diesel tank dropped right in place on mine. They were both around 25 gallons, so if that sounds right for yours I bet it would fit right in. There was a difference in the filler necks, and I think there is a difference in the pumps at the filling station so the tank will need to be swapped. I did use the master cylinder and booster off the donor truck as well. I believe the master cylinder is different to accommodated the larger brakes, and as I recall the booster off the diesel is smaller in diameter. I remember the 1/2 booster hit something on the Cummins and that's why we switched it as well. The heater lines hooked right up, but the air conditioning did not. I believe the 88 took R12 and the 92 took R134A so the whole system will need to be swapped from your diesel. One thought though, have you considered dropping the good body on the diesel chassis? A apart of me wished that I had the title and could have done that. Of course you would have two completely disassembled trucks if you go that route.

 

yes i have thought about it but i dont what to go throught the process of cutting and shorening the frame. my half ton doesnt have ac so ill either have no ac or switch the dash and all the ac components. thanks for all your information

 

No problem, good luck with it.