Spool third Member is a fully locked third member and it comes complete with: A new, U.S.A. made, nodular iron 9 inch case. A new U.S.A. made billet aluminum pinion support. A new forged pinion yoke of your choice. Pinion yokes available in 1310, 1330S, 1330T and 1350 series. 31 spline Ford 9 inch third member fully assembled. Your choice of gear ratio and pinion yoke (please indicate choices in comment section on order form).