3/8 Hi-Tech Polylocks

The 3/8 Hi-Tech Polylocks from COMP CAMS are precision rocker arm nuts engineered for high-energy engine builds where valvetrain stability under extreme load is non-negotiable. Designed for serious enthusiasts and professional engine builders, these fasteners prevent rocker arm nut loosening caused by vibration and thermal cycling—a critical failure point in performance and race applications. The set of 16 provides complete coverage for dual-quad or big-block applications, making them indispensable for any engine producing sustained high RPM or boost.

Manufactured from hardened steel with black oxide finish for corrosion resistance and durability, each 3/8-24 threaded nut incorporates COMP CAMS' proven polylock insert technology—a nylon locking feature that creates friction without degrading under repeated fastening cycles. The 3/8-inch diameter and 24 TPI thread pitch ensure compatibility with standard rocker arm stud applications, while the polylock design maintains consistent clamping force across engine operating temperatures, eliminating creep and micro-movement that can compromise valve timing and lift characteristics.

Engine builders and performance technicians rely on these nuts for street, strip, and circle-track builds where valvetrain reliability directly impacts both power output and component longevity. Installation requires a 9/16-inch wrench or socket and standard assembly torque procedures—no special tools needed. Reusable across multiple engine builds, the polylock design resists stripping and maintains locking integrity far longer than standard nylon-insert alternatives, making them a cost-effective choice for serious competitors and rebuild shops.