I have a 87 Iroc with 17x8 Iroc wheels with /245/45/17 . It seams that the new tires/rims stick out farther that stock. If i lower it 1 inch will the tires rub the fender wheels. Thanks in advance.

 

No way to tell without knowing how much farther out your tires are, but if they stick out very much (wild guess, more than an inch or so from stock) you'll probably rub in the front at least occasionally. There's more room to play in the back so you might be OK there. No guarantees either way. I lowered an inch with stock 16" IROC wheels, and the 245s never rub, but it looks pretty darn close up there. 1.5 inches tire to fender.