explorer 8.8 in an a-body: experience needed

Interesting dialog. I am looking to do the same with my '65 Valiant. The cost of 8.75" Sure Grip from a B-body is painful. If I have less than 400hp I would think this could be an affordable solution to replace my weak 7.25" stock rear end. I wish this thread gave more specific "how to" and less "you can't do that"!