Quick 6,
I have centerlines auto drag 15x8 up front and before the big brake upgrade they were split 4/4. 4 inches of backspacing, with a 265/50 and the thing looks mean. No problems with the stock ride height, and no inner rubbing on the frame on hard turns.
Then ordered 1 inch lowering springs from pst, got the car back, and it was now 2 inches lower. They sure know how to add there at pst, this was not the only spring height screw up I have heard from them. So the game changed.
If you keep the stock ride height or even 1 inch lower the 265 will be fine at 4/4, even after the 2 inch drop, I just had the tires alittle more castered in. But eventually I had the wheel well cut and now all is good. $300 later.
I guess the moral is, 4 inch bs on a 15x8 will work even with the 265/50, just make sure you do not order lowering springs from pst, your car will look like a snow plow and end up costing you tons more to correct.
I could not go to a smaller size up front, they look way to cool that huge.