WHICH REAR TO INSTALL????
8 1/4 is still capable...Trust me, I've been doing LOTS of research.
8 1/4 with a good center chunk, C-clip eliminators & aftermarket axles, should stand up to most smallblocks.
I found this article last week when researching for my Dart..
http://www.moparmusclemagazine.com/projectbuild/5148/