72 Body on 79 frame and running gear?

[dmanhogg]

Hey guys, first post here, but been lurking for a little while. I have had a 72 GMC 3/4 ton 4x4 for the last 2.5 years. I am a little different then you guys and i have mine lifted 6 inches on 40 inch tires. over the last year the truck hasnt been driven, the engine and tranny taken out, etc etc.

I've just inheritted a 79 3/4 ton 4x4 from a member of the family who has recently passed. It is fully running and functioning, it was his daily driver.

My initial thought was to put the engine and tranny in my truck, but upon inspection i've found a lot of rust in the frame, not to mention the 79 has power brakes and steering, air condition, and is just a little bit more practical.(and i LOVE 67-72 era trucks) So now i am thinking of removing the 79 body, and simply dropping my 72 body on top of the frame and all of its running gear and wiring, and building a new dash in the 72 to remount everything. I know i will need to relocate body mounts, but what else will i need to do?
Thanks Guys!