If you are the type of person who is going to race within the rules, don't forget the rule book when you make your choices. SCCA Stock Class rules permit changes to the front sway bar but not the rear, not even modification of attachment points. NASA permits changes to the sway bars but no rear tire above 255 if you want to stay in class. A limited slip diff would be very benifical in BS and other cars in class have LSD, but since the crossfire did not have a LSD offered from the factory it cannot be added without cheating. SCCA Stock requires use of the same rim size, width and offset as stock, if not I would be running the smallest, lightest and widest rims I could fit on the car. Although drifting is fun, it is seldom the fastest way around the course. I have raced against more then one heavily modified SRT-6 running 245's on all 4 corners and have beat them by several seconds on sub 60 second autocross tracks.