crew cab onto suburban chassis

[Lug]

Hello all.
Went looking at rigs today. Found a 1986 Suburban 3/4 4x4 suburban with a fresh 6.5 n.a. diesel. The downside is that the body is rusted out. To the point seeing ground thru the rear fenders from the inside. Also found on Craig's list a crew cab cab of about the same vintage that the ad says is not rusted out. The idea is to put the crew cab cab onto the 'burb chassis and make a flat bed to finish of the rear. How many body mounts would I have to move to make this work?
Justin