SBC 6-3/4 Harmonic Damper - Non-SFI

The Professional Products SBC 6-3/4 Harmonic Damper (Non-SFI) is a precision-engineered crankshaft accessory designed for small-block Chevrolet (SBC) engine builders and high-performance enthusiasts who demand reliable vibration control without SFI certification requirements. This damper serves as a critical interface between your crankshaft and rotating assembly, absorbing destructive harmonic vibrations that can compromise engine longevity and performance.

Professional Products engineered this 6-3/4-inch damper using proven elastomer-ring technology that isolates torsional vibrations generated by combustion cycles and crankshaft inertia. The non-SFI designation means this unit is optimized for street and naturally aspirated racing applications where SFI certification is not mandatory. The damper's substantial 10.86-pound construction provides the mass needed to effectively damp vibration across the RPM range while maintaining balanced rotation.

This harmonic damper is ideal for small-block Chevrolet engines ranging from 262 to 400 cubic inches. Precision-machined hub geometry ensures accurate ignition timing reference and proper belt or pulley alignment, critical factors in preventing premature bearing wear and crank failure in high-revving builds. Whether you're building a street cruiser or a dedicated track engine, this damper provides the robust engineering needed for serious SBC applications.