Ring Gear Bolt KitsSpecially hardened, precision-ground washers are included where required. The tremendous shock loads generated at launch by most any drag racing vehicle equipped with todays sticky tire compounds or the acceleration and deceleration of oval track cars put considerable strain on the ring gear. For this reason, the fastener experts at ARP have developed the Pro Series ring gear bolts. They are forged from premium grade 8740 chrome moly steel and are heat-treated to a nominal rating of 200,000 psi tensile strength.Ford9" Ford uses 5/8" socket - Thread: 7/16-20 - UHL: 0.940