It'd probably be better to use the 15x8.5's with the 3.375" BS and no spacer. I have these on my car with 275/50D15 Hoosier Quick Times and they don't rub, and come right to the edge of the quarter panel lip. Although the 275/60's are a little taller.
You'd have to use one hell of a spacer to keep the inside of the tire from rubbing the frame, I would think.
Steve