SBC 6-3/4in Harmonic Balancer - Int. Balance

The SBC 6-3/4in Harmonic Balancer - Internal Balance by PROFORM is an essential component for small-block Chevrolet engines requiring precision crankshaft vibration management. This internally balanced harmonic balancer is engineered for builders and enthusiasts who demand OEM-quality performance without the premium price tag. Whether you're assembling a stroker motor, rebuilding a classic 350, or upgrading your street machine, this balancer ensures your engine runs smoothly and reliably at any RPM range.

Internally balanced harmonic balancers work by integrating counterweights directly into the balancer assembly, eliminating the need for external balance weights on the flywheel or flexplate. This design reduces parasitic drag, simplifies engine assembly, and provides superior harmonic damping compared to externally balanced configurations. The 6-3/4-inch diameter is the standard sizing for small-block Chevrolet applications, and PROFORM's elastomer-core construction absorbs torsional vibrations that would otherwise damage bearings, seals, and internal components. The precision-machined construction ensures concentric bore alignment and balanced rotational symmetry for vibration-free operation.

This harmonic balancer is ideal for SBC engine builds, including 283, 305, 327, 350, and 400-cubic-inch variants, provided your rotating assembly and flywheel are matched for internal balance. Installation is straightforward on a freshly built or rebuilt short block, requiring proper keyway alignment and bolt torque specifications per your engine manual. For street, strip, or vintage racing applications, the SBC 6-3/4in harmonic balancer delivers the vibration control and longevity expected from a professional-grade component.