Alright folks,
I have seen a few threads on here partially answering the questions I am about to present; however, nothing seemed to quite give me the level of certainty I am looking for. For context, I recently "saved" an 84' Bullnose f-250 from rotting in a field. Blown up motor yada yada. Anyway, I paid about 350 for it and it's a total ****box . My question is what parts can I expect to be interchangeable, specifically rearends? I have an opportunity to buy a dually rearend from an 89' f350 which I'd imagine based on other threads would be interchangeable with a bullnose f350, but will it also support the lighter duty bullnoses, with little to no modification. At this point I want to turn the pos into a flatbed dually because its at a point where it needs all new everything pretty much. I've seen quite a few guys do this in the past with their f250s, now I just want to know how. Thanks a bunch.

 

Here's a thread on F250 vs F350.

https://www.ford-trucks.com/forums/9...and-350-a.html

It's good you have an F250, I think it would be more difficult if you were trying to put F350 parts on a 1/2 ton. Good luck!

 

If you start hunting around for dually rearends you have to be careful and measure the width backing plate to backing plate and spring pad to spring pad. You will run across two different ones, a wide one that matches the measurements of a regular single rear wheel pickup rearend, and a narrow dually rearend. The narrow one is for a chassis/cab truck and will not fit a pickup frame.

Ford and the other manufacturers have made the chassis cab trucks for years, and they always make them the same so a standard bed will fit any truck, any year. That would be any utility bed, flad bed, dump bed, etc. That is why they are different, they went wild with the pickups and changed them from time to time, but always kept the chassis/cabs the same as the industry standard. Most chassis/cabs I have run across are f350's.

The 89 should bolt in and fit if you have a pickup, and the dually rearend is from a dually pickup. You may run into driveshaft problems. Most of the early rearends in your year truck were Dana rearends. Most of the later rearends were Ford/Sterling rearends, which I like better because it's easier to service the brakes. But the yoke position may be farther forward and might require a shorter driveshaft and possibly a different u-joint size. You will have to try it and see.

 

Thanks for the replies thus far, got some good intel on it.