Project Black Betty
I'm all for turbo /6 but it is not an easy bolt on and then go 12's with it. It will take a bit of tinkering to get you there. Have fun!
Swapping the rear end is going to happen whether you have a turbo /6 or a v8. A 7.25 will not with stand the power of a turbo very long or at all really.
Looks like you have a good start on the project though!! Keep posting!!