Another body swap question

[Critter]

I have a lead on a pretty nice 86 C-20 for basically free and I was considering putting the body/bed on the frame and chassis of the 78 in my signature. I am aware of the rear cab mount difference and slight bumper mount difference, but is there anything else? I have searched and seen a few posts where people have done this but usually they are putting an older body on a newer chassis, opposite of me.

I hope to pull the complete cab, front clip, core support, bed etc and put it straight on the 78 frame and use all the wiring and interior from the 86. They are both 3/4 tons, both 4 speed manuals, and both single cab long beds so I'm hoping it will be pretty easy. The 86 C-20 was originally a diesel but has had a 350 in it most recently if that makes a difference. The only thing that came to mind is the hydraulic clutch setup on the 86 which I will use if I get all the parts (the guy will be pulling the engine and tranny out before I get it). Anything else I should worry about??? Sorry if this has been hashed out before, I'm just trying to get some confirmation on my particular swap so I don't waste any extra time or money. Thanks!