Ultra Series GM 10SI Alternator

1040 AMP - Polished - 1 Wire

Upgrade your build with the March Performance Ultra Series GM 10SI Alternator, delivering 140 amps of dependable charging power with a polished, show-quality finish. Designed with 6 and 12 o’clock mounting positions (6.6” center-to-center) and a simple one-wire hookup, this alternator ensures steady performance even at low idle with ultra-low cut-in voltage regulators. Built with neoprene-sealed bearings and high-efficiency copper and steel internals, it’s engineered for long-lasting durability, smooth operation, and reliable output. Backed by the March Performance Lifetime Warranty.