15X8 w 4.75 backspacing

8 3/4? 5x4.5” or 5x4” axles?

If it’s an A body 8 3/4 with BBP axles then yes. If it’s an A-body 8 3/4 with SBP axles you may need some spacers to keep the tires off the springs, depending on what you decide to run for tires.

I do have the big bolt pattern 5 X 4 1/2 on a 8 3/4 A body rear. Planning on running 245/60/15's. Would love to run 255/70/15's but I don't think they will fit. The 245's are 9.3 inches wide and the 255's are 10 inches wide