SBC SWAP IN A 64 BARRACUDA?

Maybe the OP is just trying to make something DIFFERENT by using what he has at hand. The only question was about the durability of an 8.75 differential.
Who gives a **** what it is that he does with it. Yes, he did state the plan for his project, which probably half of the responses would have been asking about anyway. Too many purists stating opinions on something that is not their concern. That is what drives people away.

It is a disaster waiting to happen. In the end it will take too much time and money if it every gets completed, and on top of that, the end product will not be as good or valuable as fixing either.