surburban suspensios and body changeout

[Sparky2]

I have an '88 surburban whose body has seen it's better days. It's a 3/4 ton, into which I recently put a newly overhauled engine and also went through the tranny.( a turbo 400). I found another '90 1/2 ton one with a much better body, which I'd like to switch around. ( I think).Which would be better; switching bodies so I can keep all my 3/4 ton stuff together or swapping running gear over onto the 1/2 tonner? Are the frames the same size etc. Where all I have to do is swap springs, diff and drive train, etc.?
Also, I'm assuming (yeah, I know what that means) the '90 has a 700 R4 tranny as it's a four speed, OD one. Would changing to my 400 turbo be a better choice if undercarrige swap is the way to go?

Any help would be greatly appreciated to help me make up my mind which way to go.