Ram Pontiac Throw-out Bearing

The RAM 488 is the standard short release bearing for Pontiac V8 manual transmission setups. If you're running a mechanical clutch linkage — Z-bar, fork, and pedal rod — behind a Pontiac 326, 350, 389, 400, 421, 428, or 455, this is the bearing that belongs in most stock-geometry bellhousings.

It carries a 1.375" inside diameter and a 1.250" overall length, riding on the 1-1/8" input shaft bearing retainer used by the Muncie M20, M21, and M22, the Saginaw, and the Borg-Warner T10. The 26-spline late GM boxes use the same 1-1/8" retainer, so the 488 covers those swaps as well.

The flat contact face is the reason this bearing is so widely used. It works equally well against a modern diaphragm pressure plate and against the original three-finger Long / Borg & Beck style plate found on factory Pontiac four-speed cars. You're not locked into one clutch design.

RAM builds the 488 for performance duty, not parts-store duty. The bearing is heat-treated and blanchard-ground for a true running face, and the race is packed with a heat-resistant moly-based grease so it survives high spring pressure and sustained high-RPM operation without cooking out.

GM 1 1/8-10, 1 1/8-26 spline
‘Short’ GM bearing
1.375″ ID
1.250″ length