I guess I'm out of ideas then. You said in your first post that you tried a 15 x 8 with a 6.5 B/S and the tire was "too close for comfort near the pipes". Then you said that a 15 X 8 with a 5.5 B/S was "to close to the fender lip". I guess the only thing left is either deal with the tire rubbing somewhere, or going with a 15 X 7 with either a 6.5 B/S or a 5.5 B/S.

The only other thing I could think of is order a set of wheels from someone like Bogart that can make you any size rim you want with any size B/S. Only problem with that is their rims aren't made to be driven on the street and I am assuming that this is for a street car.