Cop car rim size

Original cop wheels are 15x7” with a 4.25” backspace. There was a 15x8 version that came on some of the later trucks but I don’t know the backspace on those.

The 15x7” 4.25” backspace works pretty well on the 73+ style BBP brakes with up to about a 225/60/15. What brakes and tire sizes are you running?
I am running 11" discs 74 cuda spindles clamp down style calipers , I think my tires are rather large , I will check tomorrow when i get to the shop . Thanks .