These housing ends are CNC machined from alloy billet steel. They are for street use only and have OEM style inner-axle seals for oil control. Two inches wide with a 3.150" diameter axle bearing bore . The bolt pattern is 3.125" center-to-center across the top, 2.6875" center-to-center across the bottom, and 2.4375" center-to-center vertically. The bolt holes are 3/8" diameter. Designed to use a Ford style axle bearing with small GM drum brakes require bearing retainer plates (part no. 8026). The drum-brake-backing-plate center hole will need to be enlarged to fit over the 3.150" diameter bearing during assembly. Kit contains a pair of housing ends.