SF58922,  30-Spline 12 Bolt Internal Billet Axle Gear Kit, with shot peen treatment and Supra-Fin finishing For use with our ACG-30 case that used a .808" diameter pin. This kit will NOT work in standard Corvette 10 Bolt Posi-Traction  case without machining modifications.  This kit comes with a spider ping for the 12 Bolt Chevrolet and can be used in the 12 bolt Eaton Posi. If used in a Corvette to upgrade to 30 spline shafts the ACG-30-3 pin muse be used with our ACG-30 Billet Case or modify the Eaton Posi case. Call 800-525-1963 for information.