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

400 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 400+ 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.

The Elite series 400 amp alternator offers great amperage output and durability at a great price. 6 phase technology, combined with massive twin rectifier assemblies and 12 huge diodes make these alternators totally durable for daily use. These impressive alternators produce 200+ at engine idle RPM and 400+ amps at cruising speeds HOT RATED. Like most high output alternators, this unit comes with a smaller diameter pulley, and will require a 1/2 inch to one inch shorter than stock length belt for proper belt tension in most applications. Installation Notes: This unit may require an additional rectangle to oval adapter harness if the vehicle was originally equipped with the CS144 Heavy duty charging option from the factory. (this is not common) This unit is a direct plug in for any truck originally equipped with the more common oval shaped 4 pin plug as shown.

Fitment Guide: