4" to 4.5" Bolt Pattern on a 7 1/4" Rear?
All 73+ A-bodies with \6 or 318 AND disk brakes came stock with a 7.25 with big bolt pattern. Should be easier to find one of those (I gave one away not to long ago) than an 8.25 and 8.75 will require new axles and re-drilled drums to get to big bolt pattern.