A Body Rear End Options?
Hey Rob not to steer you away from this site, but you want to check out moparts.com. I have seen quite a few 8 3/4 rears go for pretty cheap there. You may be surprised of how people that are local selling parts.
You also might want to look on Ebay. I also have seen them on there. But if you just are looking locally then you might have a problem finding one.
You could find a B Body 8 3/4 and have it shortened.
Hope that helps!