I just got ahold of a 98 GT. It has cobra R rims with 275's in the back and 245's in the front. Is that the right sizes for the rims? Whats the biggest I could go? Also when you turn lock to lock the front rims are rubbing on the swaybar and pops when the wheel weights hit it. Did they make different offset cobra rims and thats the problem or do I need spacers? Thanks for any help in advance....