170 Amp High Output Alternator - 2001-2007 6.6L Duramax LB7/LLY/LBZ & 1996-2004 GM Gas - Chrome

170 Amp High Output Alternator for 2001-2007 6.6L Duramax LB7/LLY/LBZ

Fits the 6.6L Duramax in 2001-2007 Chevrolet and GMC HD trucks (LB7, LLY and LBZ) and the 1996-2004 GM gas trucks that share the same case and mount. This is a direct bolt-in upgrade over the factory unit — same mount, same pulley position, no bracket modification.

Diesel engines spend most of their working life at low RPM, and that is exactly where a stock alternator runs out of headroom. This unit holds 200+ amps at engine idle and delivers a full 170+ amps at cruising speed, hot rated — enough for a lift pump, auxiliary lighting, a winch, a plow, a welder or a competition-grade stereo without watching your voltage sag at every stoplight.

Engine codes covered: LB7, LLY, LBZ

Vehicles: Silverado Sierra 2500HD 3500HD, Suburban, Tahoe, Escalade

Manufacturer specifications and full fitment

The S series of 6 phase alternators offers incredible output in a compact and durable package. 12 diodes, (instead of the normal 6 diodes) and twin rectifier plates with outstanding airflow ensure long service life, even in severe conditions. A side output stud and seamless rear cover with a side output plug allow for better clearance from the back of the alternator to the front of the engine and a smooth appearance. 

A single wire on the provided pigtail gets connected to any ignition switched 12V+ source to turn the alternator on and off with the ignition switch. Simply run a properly sized positive and ground cable from the alternator to the terminals of the battery and the alternator will work perfectly, regardless of what kind of wiring harness you have.

Fitment Guide: