Stock wheel and Largest tire size?

I want to put a little wider tire on the back of my gto. I want to use the same brand/type and they make it in a 255/45/17. Does anyone know if this tire will fit on the stock wheel and not rub on the fender lip? Or maybe a 255/40/17 in a kdw instead of kdws?

Try this link:

http://www.ls1gto.com/forums/showthr...ight=tire+size

What is the rim size on my new GTO , is it 17x7.5 or 17x8?

17x8