Re: 71 disc brake backspacing help
What are you having problems with exactly. Rims aren't clearing something like the brake calipers, or shocks. Do they stick out to far and hit the fender lip. On my 71 Malibu I have front factory discs with new Right Stuff calipers. I run a 15x4" rim in the front with a 2.25BS and in the rear with stock brake drums I run a 15x8" with a 5.5 BS with a 1/4" spacer. Everything fits and clears everything.
71 Malibu, Cottonwood Green, 396 BBC, AutoGear M22W 4 speed, 12 bolt 3:55 posi.