switching 14" axels to 15"

I agree. Watch backspacing to keep a wide tire out of the fender and off the rear springs (in stock location). I'm using 15x7 cop car wheels with 235/60-15's with no problems. The same wheels with 255s work ok on the rear, but not on the front. My problem with putting a larger tire on the rear for a street car is that it exacerbates understeering.