GM 12SI Alternator- 85 Amps w/1V pulleylley

The POWERMASTER GM 12SI Alternator with 85 Amps and 1V Groove Pulley is an essential component for classic GM engine swaps, restoration projects, and high-output electrical system upgrades. This alternator is perfect for those rebuilding muscle cars, modernizing vintage pickups, or installing carbureted big-blocks into custom chassis.

Engineered with an internal voltage regulator and one-wire installation capability, this 85-amp unit simplifies wiring for custom builds where OEM harnesses may not apply. The robust construction ensures reliable performance in high-heat environments typical of modified engines running tight hood clearances.

Street rodders, restoration shops, and weekend warriors will benefit from this alternator's ability to handle multiple accessories—such as electric fans, fuel pumps, ignition systems, and auxiliary lighting—without voltage sag. Its compact size and standard 1V Groove Pulley make it compatible with various belt drive configurations.