tires for 75 duster

Hey guys, Ihave a 75 duster with a 340, with 15x7 police wheels. If i remember right, I have 225/65 15's on the front, and when i am turning shart when not moving fast, they rub the very bottom off the front fenders, anybody know what is the largest tire I can put on this car without rubbing opn the front?

Thanks