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I have a 78 SC converted to Turbo Flares and wanted to know what are the largest size tires on an 18" wheel that you have put on?

 

I had turbo flairs on my 78 SC at one time and ran with 285 width RA-1's mounted on 18x11 Jonbloed wheels. I tried 305's but had to raise the car in order to keep them from rubbing when the car was at full squat. Will you be racing your car?

 

I am aiming for 255/35/18 front and 335/40/18 back. The guy that is seating up the suspension is telling my it should be ok, if not for sure the 315 in back. He is working on the front struots now and later i will take the car for a full set up and corner balancing.

 

It may work depending on what tire you use (each manufacturer measures their tires differently), suspensions settings, and ride height. You car may not see any performance benefit from the wider tires. I could get my car set up pretty low using a 245/285 tire combination.