Ford SB 289 302 Windsor Supercharger Crank Hub 1v Groove Accessory Drive Pulley aluminum and 100 percent pressure-

aluminum and 100 percent pressure- tested to eliminate leak

These Speedmaster aluminum pulleys are made from a 356 aluminum alloy that is heat-treated to T-6 specs

Like all Speedmaster cylinder heads

Speedmaster Aluminum Roller Rockers are extruded from 6061 T6 Aluminum

It is similar to our LowRise

Ford SB 289 302 Windsor Supercharger Crank Hub 1v Groove Accessory Drive Pulley aluminum and 100 percent pressure-Speedmaster aluminum crankshaft pulleys are manufactured from 356 aluminum that is heat treated to T 6 specs. These Speedmaster aluminum crankshaft pulleys help to increase horsepower by reducing accessory drag.