ARP 135-3606 Cylinder Head Bolt Kit Chrome Moly Steel - 8740

The ARP 135-3606 High Performance Series cylinder head bolt kit delivers professional-grade fastening strength for demanding engine applications. Manufactured from premium 8740 chrome moly steel, these head bolts are heat-treated to 180,000 psi tensile strength—15% stronger than Grade 8 fasteners—providing superior clamping force and reliability under extreme conditions.

Key Features:

• Premium 8740 chrome moly steel construction with 180,000 psi tensile strength
• Hex head design with reduced wrenching profile and wide-area flange
• Allows cylinder head retorquing without valve train removal
• Thread rolled after heat treatment for exceptional fatigue resistance
• Centerless ground for precise concentricity and perfect component alignment
• Includes hardened parallel-ground washers for even load distribution
• Cold-forged construction ensures molecular integrity

Manufacturing Excellence:

ARP's precision manufacturing process sets these fasteners apart. Each bolt is vertically rack heat-treated for complete and consistent heat penetration, then centerless ground through multiple passes to achieve exceptional straightness and concentricity. Thread rolling is performed after heat treatment—a costly but critical step that delivers approximately ten times better fatigue strength compared to pre-heat-treat threading methods used by competitors.

Application Benefits:

The wide-area flanged head design eliminates the need for valve train disassembly during cylinder head service, saving valuable time during engine maintenance and rebuilds. The reduced wrenching hex provides clearance for larger diameter valve springs and other performance components. Included hardened washers ensure accurate torque readings and uniform clamping force across the entire head surface.

Installation Note:

Head bolts are ideal for street-driven vehicles where engine bay obstructions like master cylinders require cylinder head removal with the engine in the chassis. For ultimate accuracy and ease of assembly, ARP recommends retorquing after initial engine operation to compensate for head gasket compression.

Trusted by professional engine builders across all forms of motorsports, ARP fasteners meet the company's zero-defect, zero-failure quality standard. Each bolt is stamped with the ARP logo as your assurance of authenticity and precision engineering.