I have 15X10 with a complete frame notch and a little widening of the wheel tubs. The first rims I had on the rear were BS Street lites with 5.5 B/S which fit the wheel well but wouldn't clear the brake rotor.
The rims I have on it now are a 5" B/S and fit both inside and wheel lip. The tire is a 28X11.5 slick.
You may have to roll the lip with a 4.5 B/S and do a half frame notch. Which done right won't take away any strength. I used a 3/16" plate as well as 1 1/4" tubing on the inside which was left over from my cage. If you do a frame notch to the seam you should only need the 3/16" plate.
For street tires I plan on running a 295X65 drag radial which may not work without a frame notch.
A 29.5X10.5 M/T slick on a 15X10 rim and 5" B/S wouldn't fit with the frame notch on mine. A 30X10.5 Goodyear slick on the same rim just barely fit.
Here's a picture with the 15X10 and 5" B/S with the 28X11.5 slick.
