BBK Under Drive 6-Rib Serpentine Pulley Kit - Polished Aluminum - Small Block Ford - Ford Mustang 1979-93 10000104 1/2" length with 5/8" female

1/2" length with 5/8" female pilot

Shock mounts sold separately

Lower Shaft Bearing

IP-67 case

BBK Under Drive 6-Rib Serpentine Pulley Kit - Polished Aluminum - Small Block Ford - Ford Mustang 1979-93 10000104 1/2" length with 5/8" femaleInstall a set of BBK performance underdrive pulleys and see an average of 8 15 additional horsepower over the stock pulleys. Under drive pulleys increase engine output by reducing the draw of the engines accessories by slowing them down and reducing the HP they use. Additional and significant performance improvements can be seen by reducing the weight of the pulley versus the original pulley which is why we recommend the BBK CNC Machined billet