Can anyone tell me of some issues I may run into swapping motors from the 90 to the 85 or swapping the 85 body to the 90 frame? I already started the process but would like a heads up if I'm about to run into issues

 

The bodies should be about the same. Dodge didn't change the body much for 20 years. Mechanically, there's quite a bit of difference. You'd have to swap the wiring harness and exhaust from the '90 to the '85. Personally, if you have the means to swap the body, I'd go that route with the '85 body on the '90. While the body is off, I'd make sure the body mounts aren't eat up with rust. You can probably pick and choose some of the body parts as I would assume the beds would be the same. Around 1991 or so, there were some minor changes to keep selling the trucks but I think you'll have a lot of spare parts.

 

it will all swap over. the bigger thing is where you wan to keep the engine TBI or going carb. personally i like the how much nicer TBI is when it is working like it should.