Biggest I'd go is 245/50-17 since stock is 245/45-17. That'll go from a 25.68" tall tire to a 26.65" tire
Any size other than stock is going to throw off the speedometer though. You need a speedo adjustment for anything not stock size.
Bullitts are better than Bullets
Faster than a speeding...............
2001 Bullitt being prepped for track duty
Corners > Straight line
HID end all thread