What is an ideal wheel back space when running 8" wide rims?

[pontiacgp]

use a piece of wood and a plumb bob. You can mark the opening on the wood and use the plumb bob to measure where the wheel meets the drum and mark that on the wood and then just measure to find the BS you need to keep the 8" wheel in the center of the opening.

 

[clean8485]

I have the 15" by 8" aluminum Corvette rims (1976-1981) on my '80 Malibu. I'm running a 245/60 tire on the rear, and a 225/60 tire on the front. No issues at all. I have a friend who's running the steel 15" by 8" Corvette rallys on his '78, with 235/60 on the front and 255/60 on the rear with no problems.

 

[Pc3]

I have 15x8 4.25 bs in the rear on a 79 cutlass. 275/60/15 tire 4.5 bs would be perfect in my case.