8.5 from a 1974 Chevelle into a 1972 Chevelle?

[Justin S]

Hello, please only answer this if you KNOW the answer, I don't need people telling me to look up the answer because I can't find it. I have a 72 Chevelle with an 8.2 open rear with 2.56 gears (worst ever I think) and I have the opportunity to buy a rebuilt 8.5 posi rear with 4.10s from a 1974 Chevelle. I know that it won't bolt right in, and its not the same length, but would I be able to get it in with adjustable upper trailing arms, or would other things be different as well, like spring or shock location? thanks!
8.2 and 8.5 internal parts are NOT interchangeable