Dbl Groove Crank Pulley

The Dbl Groove Crank Pulley by MOROSO (MPN 64550) is a precision-engineered crankshaft accessory designed for engine builders, performance enthusiasts, and mechanics who demand accurate ignition timing and accessory drive reliability. This dual-groove pulley serves as a critical component in mechanical distributor ignition systems, allowing you to dial in proper timing marks while supporting alternator and water pump operation through its secondary groove configuration.

Manufactured by MOROSO—a brand trusted for over 60 years in performance engine components—this pulley features precision-machined grooves that ensure positive belt engagement and eliminate slippage during high-RPM operation. The dual-groove design simplifies installation by reducing the number of pulleys needed in some configurations while maintaining the structural integrity required for both timing accuracy and auxiliary load distribution.

This component benefits classic muscle car restorations, vintage race engine builds, and any carbureted or fuel-injected platform still running mechanical distributor ignition. Installation is straightforward—it bolts directly to the crankshaft snout and works with compatible harmonic balancers and pulley systems found on small-block and select big-block engine families.