The center section is offset to one side. You have to cut somewhere in the neighborhood of 2 to 2.5 inches off of it to center everything. The later models come with disc brakes, the one I got had drums on it.
I went this way with the 8.8 in my Dart, if you can find a ranger 8.8 it's the right width already and the center isn't offset.
On another note if you have a mild motor, 300hp or less on street radials I bet a 7.5" would hold up fine - they're much stronger than 7.25 chrysler rears, V8 mustangs came with 7.5's from 79-85 and they hold up ok until you put slicks on them.
