I currently run 225/50-13 hoosiers on an 84 in ITA. You will need to roll the inner fender lip (allowed). I've found the best/least damaging method is to gently roll the car back and forth with a wooden baseball bat between the tire and fender. Additional clearance can also be had by moving the fender as far outboard as the mounting holes will allow. As long as you don't cut metal or modify holes, it is also legal. Also, check for the tire rubbing on the spring, or lower spring perches. Double check this clearance (remove the front tires and look for rub marks on tire and spring perch) after your first on track session. Bring wheel spacers just in case (better to stick the wheels out than to cut a tire...). Large bearing strut housings have slightly more clearance here than small bearing units (1/2 degree greater angle between spindle and strut tube).
Tachi
#29 ITA SFR SCCA