15" rally backspacing?

[1981silverz28]

I have 15x8 Vette rally's on my 81 camaro w/ 265-50-15 .I want to widen the rears out to 15x10.what backspacing do I need and I will roll the lip if I need to. Also what size tire do I need to run to keep the sidewall about the same height and be wide enough for the wheel.

[1981silverz28]

Anybody???????????

[Kenova]

I don't have any personal experience with your combo, but this chart should help out.
https://www.pro-touring.com/tech/wheels/Wheel_Survey.htm

Ken