9" Ford 31 Spline Billet Trac Lock Carrier
1966-1977 bronco, many other ford cars and trucks
9" Ford 31 Spline Billet Trac Lock Carrier. (posi). if you are running a bigger tire or your adding more horsepower then this billet carrier is a huge upgrade over the factory cast trac lock carrier or open carrier! the weakest link with the oem trac locks is the cast hat, they are prone to cracking and then ultimately breaking in two. this machined billet case and hat are far stronger then the factory units. this carrier fits all ford 9" rear ends no matter the gear ratio.