I heard the 03/04 Cobras come with 275 size tires around the 4 corners. I was looking to get 275 for my 01 gt. I wanted 17 x 10.5 in the back, but i called up numerous online places, tire direct, tire rack, etc, and they said a 275 will not fit anything above a 17 x 9.5, which is really pushing it. Is this true, and that the only way i can throw 17x 10.5 on the back is going wit 315. Is this true?