ARP 114-3605 Cylinder Head Fasteners High Performance Series Hex Head Bolts - 8740

The ARP 114-3605 High Performance Series cylinder head bolt kit delivers professional-grade fastening strength for demanding engine builds. Manufactured from premium 8740 chrome moly steel, these hex head bolts are heat-treated to 180,000 psi—15% stronger than Grade 8 fasteners—providing exceptional clamping force and reliability under extreme conditions.

Key Features:

• Premium 8740 chrome moly steel construction rated at 180,000 psi
• Hex head design with wide area flange eliminates need for valve train removal during retorquing
• Cold-forged to ensure molecular integrity and superior fatigue resistance
• Heat-treated prior to thread rolling for maximum strength
• Centerless ground for precise concentricity and perfect alignment
• Thread rolled after heat-treat for 10x better fatigue strength
• Includes hardened parallel-ground washers for even load distribution and accurate torque readings
• Select applications feature undercut short bolts to equalize stretch and prevent head gasket failures

Manufacturing Excellence:

ARP's precision manufacturing process sets these fasteners apart from competitors. Each bolt is vertically rack heat-treated to ensure complete penetration and uniform properties throughout. The centerless grinding process involves approximately ten precision cuts to achieve exceptional straightness and concentricity, allowing cylinder heads and gaskets to align perfectly during assembly. Thread rolling after heat-treat, while more expensive and demanding on tooling, produces vastly superior fatigue resistance compared to pre-heat-treat threading methods used by other manufacturers.

Installation Notes:

The reduced wrenching hex head with wide flange design allows for cylinder head retorquing without removing valve train components, and accommodates larger diameter valve springs. Always re-torque head bolts after initial engine run-in, as head gaskets will compress during the first heat cycle. Use the included hardened washers to ensure consistent torque readings and even clamping force across all fasteners.

Trusted by top professional engine builders across all forms of racing, ARP head bolts represent the pinnacle of fastener technology. Each bolt is stamped with the ARP logo as assurance of quality and adherence to their zero-defect, zero-failure standard. Complete kit includes all necessary fasteners and washers for a secure, reliable installation.