What size spacer is best for 18 by 10.5 on a camaro

 

The factory 18x10.5" C5 Z06 wheels have a 58mm offset. That produces about ~8.02" backspace. Running 7.93" backspace on my Formula required hammering the inner fender liners, and cutting the projecting edge of the jounce bumpers. You need to gain about 1/4" to avoid problems altogether, but running spacers on the rear isn't always a good idea.