Alternator Pulley

The MARCH PERFORMANCE Alternator Pulley (MPN 137) is a precision-engineered V-belt pulley designed for builders and enthusiasts looking to optimize alternator performance and engine bay aesthetics. This single-groove pulley replaces OEM units and serves as a critical component in serpentine belt drive systems, controlling alternator output speed and maintaining proper belt tension across multiple engine accessories. Whether you're restoring a classic engine, upgrading a street machine, or fine-tuning a high-performance build, this pulley ensures reliable charging system operation while delivering a refined, finished appearance under the hood.

Machined from lightweight aluminum and finished in a clear powder coat, this alternator pulley measures 2.688 inches in diameter and features a single V-belt groove optimized for smooth power transmission with minimal slippage. The clear powder coat finish resists oxidation and corrosion while maintaining the natural aluminum appearance—a hallmark of quality fabrication in serious builds. The pulley's compact dimensions (4.35 x 4.25 x 4.55 inches) and lightweight construction (0.61 lbs) reduce parasitic load on the engine while maintaining structural integrity under sustained belt tension. MARCH PERFORMANCE's engineering ensures concentricity and balance, critical for eliminating vibration at high RPM and extending alternator bearing life in both street and racing applications.

This universal kit includes a protective cover, simplifying installation while safeguarding against accidental belt contact during engine operation. Mechanics and fabricators appreciate its compatibility with standard V-belt serpentine systems, making it suitable for small-block and big-block conversions, LS swaps, and carbureted-to-fuel-injected transitions where OEM pulleys don't fit the new configuration. The pulley's 1-groove profile works seamlessly with matching belt drive packages, delivering consistent charge rates while maintaining a clean, professional engine compartment finish—ideal for show cars, restomod projects, and performance builds where function and form demand equal attention.