Poly Locks - 3/8 (4pk)

The SCORPION PERFORMANCE Poly Locks 3/8 (4-pack) delivers race-series fastening security for high-performance engine builds. These polylock rocker arm nuts feature a 3/8-24 thread size and employ a nylon insert locking mechanism that resists vibration-induced loosening without the need for secondary lock washers. The black oxide steel construction provides corrosion resistance while maintaining the precision fit demanded by competition and professional engine builders.

Each set contains four complete nuts, sufficient for typical valve train configurations where multiple fastening points require synchronized torque specifications. The polylock design allows for single-pass installation—the nylon insert engages immediately upon threading, eliminating the need for re-torque procedures common with conventional fasteners. This characteristic is critical in engine environments where thermal cycling and sustained vibration would otherwise cause progressive loosening. The 3/8-24 thread pitch is the industry standard for rocker arm applications across both small-block and large-block platforms.

These polylocks are engineered for engine builders and performance enthusiasts restoring or building high-output engines where fastener reliability directly impacts engine longevity and safety. Whether assembling a race engine, street performance build, or rebuilding a classic powerplant, polylocks eliminate the risk of rocker arm nut failure that can result from conventional fasteners. The 4-pack format provides the fasteners needed for a complete rocker arm installation with spare capacity for future service or multi-engine projects.

Polylock fasteners represent the modern standard in competitive engine building, offering superior vibration resistance compared to lock washers or castle nut designs. The nylon insert self-locks at a lower prevailing torque, reducing the risk of over-torquing and thread stripping while ensuring that fasteners remain secure throughout extended engine operation. SCORPION PERFORMANCE's reputation in race-series components makes these nuts a trusted choice for builders who require absolute fastening integrity.