Where did you guys find your 8 3/4's?

If you're planning on going to big bolt pattern, you're kind of throwing money away buying a complete A Body rear. You said you don't need the brakes, and you aren't going to use the axles.. Basically, that means you need the housing and a third member. It's only 10 nuts to remove the third member, and it's probably something you'd want to do before spending the time and money to put a bunch of un-inspected used junk in your car. Plus, if you buy the third member separately, you get what you want, not some gamble.

Of course, jtkaaa07 says he has something for you. Definitely worth checking into.