1:1 Crank Pulley

The ALLSTAR PERFORMANCE 1:1 Crank Pulley (ALL 31084) is a precision-engineered crankshaft pulley designed for small block Chevy engines requiring direct 1:1 belt-to-crankshaft speed matching. This two-groove, V-belt pulley features a 6.625-inch diameter aluminum construction with a natural finish, engineered to work with short water pump configurations. The 1:1 ratio ensures accurate engine accessory timing and is essential for builds where synchronized crankshaft and accessory drive speeds are critical to performance and reliability.

Constructed from aluminum, this pulley delivers a lightweight solution that reduces rotational mass while maintaining the structural integrity required for consistent belt drive performance. The two-groove V-belt design provides positive engagement with standard serpentine or multi-rib belt systems common in street and racing applications. The short water pump configuration makes this pulley compatible with small block Chevy engines using space-constrained pump mounting, a frequent requirement in restorations, engine swaps, and custom engine builds where factory dimensions must be respected.

This pulley suits builders and enthusiasts restoring or modifying small block Chevy powerplants who need precise accessory drive timing without the added complexity or cost of external timing adjustment systems. The 1:1 ratio is standard in naturally aspirated small block applications and eliminates the guesswork when replacing worn or damaged factory pulleys. Whether for street performance, weekend cruising, or reliable daily-driver service, the ALLSTAR PERFORMANCE crank pulley delivers straightforward, verified compatibility with small block Chevy engine platforms.