Poly Locks - 7/16 (4pk)

The SCORPION PERFORMANCE Poly Locks 7/16 (4-pack) is a race-series rocker arm nut engineered for high-performance engine builds where traditional hardware fails under extreme valve train loads. These 7/16-20 thread polylock nuts use a nylon insert locking mechanism to prevent vibration-induced loosening, a critical concern in forced-induction, high-RPM, and competition engines where rocker arm preload consistency directly impacts valve timing stability and cylinder head integrity.

Manufactured from steel and finished in black oxide, each nut in this four-piece set delivers the repeatable clamping force required to maintain precise rocker arm geometry across thermal cycling and extended engine operation. The polylock design provides a self-locking feature that eliminates the need for lock washers or safety wire, simplifying assembly while meeting the vibration resistance demands of modern race applications. The 0.27 lb total weight reflects the compact, precision-machined construction typical of Scorpion Performance's competition-grade hardware.

Intended for engine builders, motorsport competitors, and performance enthusiasts working with small-block and mid-size engine platforms, this 7/16-20 polylock nut set addresses the fastener failures that can compromise cylinder head durability during dyno testing or track duty. The black oxide finish provides light corrosion resistance suitable for engine bay environments, though additional protection may be warranted in salt-air or long-term storage conditions. This is a consumable component—having a spare four-pack on hand prevents assembly delays during rebuild work.

Polylock nuts remain the industry standard in racing and performance engine assembly because the nylon insert provides consistent preload retention without the complexity of alternative locking methods. The 7/16-20 size fits rocker arm studs common to small-block Chevrolet, Ford, and Mopar platforms, making this set a foundational fastener for any serious engine rebuild or upgrade.