BBM CM Rocker Arm Shafts 2pk

The PRW Industries BBM CM Rocker Arm Shafts 2-pack is a chromoly performance upgrade designed for Mopar B and RB-series engine builds. This pair delivers the material strength and dimensional precision required for high-RPM applications where cast iron stock shafts risk failure under sustained load. Chromoly construction increases tensile strength while reducing overall weight compared to OEM components, a critical advantage in engines pushed beyond factory specifications.

The rocker arm shaft is a fundamental valve train component that supports and guides rocker arm movement across the cylinder head. In high-performance Mopar B and RB-series engines—particularly those running elevated valve spring pressures, aggressive cam profiles, or sustained high-RPM operation—OEM cast shafts can develop fatigue cracks or permanent deflection. Chromoly shafts resist these failure modes by offering superior fatigue strength and stiffness. The two-pack format covers both exhaust and intake sides, providing complete valve train coverage in a single purchase.

This upgrade is essential for serious Mopar B and RB-series builders undertaking engine rebuilds for street performance, bracket racing, or engine swap applications where reliability at elevated power levels is non-negotiable. Engine builders, performance shops, and hands-on enthusiasts restoring or modifying these platforms rely on chromoly rocker arm shafts to prevent valve train failures that can damage cylinder heads and halt projects mid-season. PRW Industries' rocker arm shafts are recognized in the Mopar performance community as OEM-replacement components engineered to withstand the demands of built engines.