Rocker Shaft - .625 x 4.020 OAL

The T AND D MACHINE Rocker Shaft — .625 x 4.020 OAL (Part No. 10300) is a precision steel component engineered for high-performance engine rocker arm assemblies. This shaft serves as the pivot pin for Sport Comp rocker arm systems, where precision bore diameter and overall length are critical to proper valve train geometry and reliable operation under sustained RPM loads.

The .625-inch outside diameter and 4.020-inch length are OEM specifications for T&D rocker arm installations. Proper shaft sizing directly impacts rocker arm stability, geometry, and the precision of valve lift and duration across the entire power band. Steel construction provides the rigidity required to maintain consistent bearing fit and minimize deflection during high-lift, high-rpm operation. Lightweight at 0.3 lbs, this shaft minimizes rotational inertia without sacrificing strength or durability in competition or high-output street engine applications.

This component is essential for builders assembling Sport Comp rocker arm packages on small-block and mid-size performance engines. Whether for drag racing, road course work, or high-rpm street builds, the rocker shaft must maintain tight tolerances and consistent support throughout the valve train. T&D Machine parts are specified by engine builders and race teams where precision and reliability under boost or naturally aspirated load are non-negotiable. Each shaft is individually sold, allowing builders to source the exact quantity needed for their specific rocker arm configuration.