My new wheels just got in. I mounted by "old" tires on the front. They are 245/50/17. (Not C5 stock, but close). Now here's my question....I want more profile on the rear than the 275/40/18. My only option would be to go to a 295/45/18. Do any of you guys have this size tire on the rear? If not, do you know if it will fit. Discount Tire said they would, but it was a punk kid working there and I would not want to take is word for it.