A few questions about a 4x4 conversion

[zeusflash]

I currently own a 69 3/4 ton 2 wheel drive pickup and want to do a chassis swap to four wheel drive. I have been searching for a 71 or 72 3/4 ton 4x4 to donate the chassis. So far I have not had much luck. Today I went to look at a 72 GMC 3/4 ton 4x4. It is on the Spokane area Craigslist offered for $1350. The GMC has an automatic trans,power steering,power brakes,some A/C and rust,the bad has been swapped and is very solid though. The big dilemma is the cab. It is an A/C cab and also has running lights so I am considering doing the rust repair and using the cab. My understanding is that Chevy and GMC cabs are the same(and I need the high hump floor anyway). Is this correct? The other question is about the rear end. My 69 has a HO52 with a locker which I would like to use. The GMC has a Dana 60. Will a leaf spring HO52(2 or 4wd) bolt to the springs in place of the Dana 60. I suppose the Dana could be limited slip but I don't know since the SPID tag was gone. My 69 also has a 427 and a Turbo 400 in it so a motor and trans upgrade may also happen. I think that I could get the GMC for $750-$1000. Any answers,thoughts ,opinions would be greatly appreciated, especially from you guys who have done this type of swap.