Drivetrain advice for engine swap

I would not run a 8 1/4, seen to many problems! First off they have a "C" clip axles, the center section breaks loose from axle tubes. 8 3/4 is your best bet!! I have run a 9" in them before, cheap and easy swap for a duster, get one out of a early 70's mustang they are 54" inside backing plates. Which is 3" wider and the wheels line up with the front. Also don't have to move the spring seats. But does not work for dart, scamp. If you wait at the right time and be patient you can pick a 8 3/4 up for $300.00-$700.00 if you just look and ask around. If you go with the 904 trans you don't have to swap the drive shaft!! Hope this helps, you also can get a short block crate, edelbrock heads, intake etc a little cheaper than the whole crate motor!!