• High Output Alternator for GMC Sierra (1999-2000) 4.3L 4.8L 5.3L
  • High Output Alternator for GMC Sierra (1999-2000) 4.3L 4.8L 5.3L
  • Action Shot: GMC Sierra Driving Fast

High Output Alternator for GMC Sierra (1999-2000) 4.3L 4.8L 5.3L

$360.95
$360.95
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This 300 amp high output alternator is built for the 1999-2000 GMC Sierra with the 4.3L V6, 4.8L V8 or 5.3L V8 engine. It delivers more charging current than a typical factory alternator, making it a strong choice for work trucks and builds that add lighting, audio, winches or other high-draw accessories.

Why Upgrade to a 300 Amp High Output Alternator?

The factory alternator on the Sierra is sized for the stock electrical load. Add accessories and it can struggle to keep up, especially at idle, so the battery makes up the difference. A 300 amp unit gives you more charging capacity, helping keep voltage steady and the battery charged.

Key Features

  • 300 amp output: 175 amps at idle and 300 amps at 1200 RPM
  • Hairpin stator design
  • Replaces the factory 105 amp or 145 amp alternator (Delco AD244 series).
  • Will not replace the factory 124 amp alternator found on some models.
  • Clockwise rotation, 6-groove pulley and 4-pin connector.
  • For best results, adding a 4 gauge charge cable and a belt one size shorter is recommended.
  • Brand new and 100% tested
  • Made in USA

Fitment: 1999-2000 GMC Sierra 4.3L 4.8L 5.3L

  • 1999-2000 GMC Sierra 4.3L
  • 1999-2000 GMC Sierra 4.8L
  • 1999-2000 GMC Sierra 5.3L

Please confirm your engine size and compare your original part number to the OE list below before ordering.

Specifications

  • Amperage: 300 A (175 A at idle)
  • Voltage: 12V
  • Stator: Hairpin
  • Condition: New
  • Country of origin: USA

Package Includes

  • 1 x Alternator

OE/OEM Interchange Part Numbers

321-1798, 321-2104, 8247, 10480388, 10464438

Frequently Asked Questions

Will it replace my factory alternator?

It replaces the factory 105 amp or 145 amp unit (Delco AD244 series). It will not replace the 124 amp alternator found on some models, so check your original before ordering.

Do I need to upgrade my wiring?

Adding a 4 gauge charge cable and a belt one size shorter is recommended for best results.

Where is it made?

It is made in the USA.

What's included?

One alternator.

Fitment

Make

GMC

Engine Size
  • 4.3L
  • 4.8L
  • 5.3L

Year
  • 1999
  • 2000

Warranty

All products are backed by our Limited Lifetime Warranty. We stand by our quality. [See terms]
High Output Alternator for GMC Sierra (1999-2000) 4.3L 4.8L 5.3L

$360.95