Aluminum Racing Alternator Pulley

Upgrade part. Billet aluminum reduction alternator pulley for the M10 engine. It is larger in diameter than stock (5"), so it slows down the alternator for reduced power loss at high RPM (most alternators produce full electrical power at modest RPM, so it's a waste to spin them faster). These are direct-fit for the later 65amp alternator with internal voltage regulator. They also fit the factory 45A 2002 alternator if you widen the keyway. Can fit on the M10,M20, and M30 engines. Made in the USA.