15x10 with a 4.5" bs will fit a 28x10 tire with the stock frame and rolled lip.
Depending how hard your car comes down in the rear on launch i did have my tire touch the upper wheel well which i think a really stiffer shock setting would have helped (was using Koni's back then).
If you have a frame notch i would go with a 5.5 or 6" b.s.
My frame is notched and i have a 4.5" B.S. wheel and with disk brakes in the rear i can tuck it in with a 6" B.S. or maybe a 6.5 B.S. (will see).
Need some rims with a 4.5" B.S.?:smile: