have a 7&1/4 in a 73 dart & the mag wheels/tires are very close to the outer fender. I would like to swap to an 8&3/4. Are these pretty much the same total width? thank you for your time. RR
The info you need is right here: An accurate 8 3/4" rear axle width list
Drum to drum, the A body BBP 7.25 is 56 3/4", the A body BBP 8.75 is 57 13/16" (about an inch wider overall, or about 1/2" each side).
Since the 8 3/4 never came in the big bolt pattern in an A body, it's probably not an A body rear end, unless someone redrilled the axles and drums. You'll need to measure to confirm.