15" Billet Spc. Street Lite Wheel over 13" Brakes

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I wanna get the Billet Specialties Street Lite Wheel and I want to run them on my 03 Cobra. I have heard to fit a 15" skinny on the front you have to use a 1" spacer. Is this true for all the skinny wheels for the 03 Cobra or is it just the welds. I have heard some people say you can only do this witht he welds. If I cant do it with the 15's than can I do it with a 16" wheel? I know I will need at least a 16" wheel for the rear. Will I have to do any grinding with the 15's even if I use a 1" spacer?