Been years so... Put a dana 60 from a 69 body under my challenger (73) i used offset front hangers for A-bodies. I made rear rails and used straight hangers for the back. My understanding is the offset front hangers and offset rear hangers is all that is needed...that and perhaps slight grinding of the locating hole in the perches. I made sure my rear leafs were parallel for reduced rear roll steer, used the stock perches in stock location.....really cant remember if I did anything to the perches at all.... Allowed 15x10's with 295's with no clearance issues
Curt
To me too 
Op, as far as the longer 1971/72 B body Dana 60 there the same width as all The E body Dana 60. So that means it will work if your willing to make it work 
