370 Amp High Output Alternator - 2001-2007 6.6L Duramax LB7/LLY/LBZ & 1996-2004 GM Gas - Black Billet

370 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 370+ 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

Installation Notes:

This unit comes equipped with a smaller 1.75 inch diameter alternator pulley, and will require a slightly shorter drive belt for proper belt tension.  Not recommended for sustained use above 5,000 RPM engine speed.

E Series

Newly redesigned for 2020, The Elite series offers the highest possible amperage and durability available in a large case alternator. 6 phase technology combined with massive twin rectifier assemblies and 12 diodes makes these alternators totally durable for daily use, while still maintaining 200+ amps at engine idle speeds. Some models are available with adjustable voltage, ask a sales rep for more details.

Installation Notes:

This unit comes equipped with a smaller 1.75 inch diameter alternator pulley, and will require a slightly shorter drive belt for proper belt tension.

This unit may require a rectangle to oval adapter harness if the vehicle is equipped with the HD charging option from the factory. (not common)