The March Performance 139 is a single-groove V-belt alternator pulley precision-machined from 6061-T6 billet aluminum. Designed for strength and long-lasting performance, this pulley also adds a polished, custom appearance to your engine bay.

Key Features:

• CNC-machined from 6061-T6 billet aluminum
• Polished finish for a clean, show-quality appearance
• Lightweight yet durable
• Helps reduce alternator drag in high-RPM applications

Specifications:

• Pulley Type: Alternator
• Belt Type: V-belt
• Grooves: 1 (single-groove)
• Material: 6061-T6 billet aluminum
• Finish: Polished

Applications:
Perfect for street rods, muscle cars, or performance vehicles using a V-belt drive system. This pulley is designed to fit most GM-style alternators but always confirm bore size and belt alignment before ordering.