215/60r15 Front w/ 275/60r15 Rear

Those springs are biased side to side and as designed, the car sits lower on the driver's side so as to launch straight in a drag situation. Usually, the difference is "around" 1.5" so if it's sitting level, something's up. That said, I love the stance. It really looks good. I always try to get as close to same diameter as I can running different sizes in case I have to run the spare, it won't make a difference.