All of these cars are just a little bit different. I run 275-60-15 BFG Drag Radials. I use an 8" rim with 3.5" back spacing (fender lip rolled), but when exiting steep driveways, they rub on the outer side of the fender. I have 1" between the tire and the frame.
If I was going to run the stock frame rails (soon to be narrowed), I would run 4 inches of backspacing with the same combo. I think that with 4" back spacing, the tire would tuck nicely under the fender.
There was a guy at Irwindale raceway this last Thursday running ET PROs. They were 11.5" wide (not sure of the height)on an 8.5x15 rim with 3.5 back spacing. His fit almost in the fender lip. His fender was rolled.
