Well to let you know I put my 275/40-17's on the front (was bored and the car was in the air with the wheels off anyways) and they stuck out the front fenders by an inch but didn't hit at full lock. So it looks like you'll have to widen the fenders atleast that much. Probably the easiest way is to widen it with a strip of steel on this seam and have it taper in at the front and back. BTW, what rims are you using with these tires? Offset?