ARP 135-3605 High Performance Cylinder Head Bolt Kit Chrome Moly - 8740

The ARP 135-3605 High Performance Series cylinder head bolt kit delivers professional-grade fastening strength for demanding engine applications. Manufactured from premium 8740 chrome moly steel and heat-treated to 180,000 psi tensile strength—15% stronger than Grade 8 fasteners—these head bolts provide the reliability and consistency required for high-performance and competition engines.

Key Features:

• Premium 8740 chrome moly steel construction with 180,000 psi tensile strength
• Hex head design with wide area flange for optimal load distribution
• Reduced wrenching hex allows cylinder head retorquing without valve train removal
• Threads rolled after heat-treat for superior fatigue strength
• Precision heat-treated vertically in racks for complete penetration and consistency
• Centerless ground for exceptional concentricity and straightness
• Includes hardened parallel-ground washers for accurate torque readings
• Undercut short bolts (where applicable) equalize stretch and prevent head gasket failure

Manufacturing Excellence:

ARP's meticulous manufacturing process sets these fasteners apart from competitors. Each bolt is vertically rack heat-treated to ensure uniform properties throughout, then centerless ground through multiple precision cuts to achieve near-perfect concentricity. The thread rolling process occurs after heat treatment—a costly but critical step that increases fatigue strength dramatically compared to pre-heat-treat threading methods used by other manufacturers.

Application Benefits:

The reduced wrenching hex and wide area flanged head design eliminates the need to remove valve train components when retorquing cylinder heads, saving significant time during engine assembly and maintenance. The precision manufacturing ensures that cylinder heads and gaskets align perfectly during installation. Hardened washers provide even load distribution and prevent embedment for consistent clamping force.

Installation Note:

Always retorque fasteners after initial engine break-in, as head gaskets will compress during the first heat cycle. Follow manufacturer torque specifications and use ARP Ultra-Torque or moly-based assembly lubricant for accurate torque readings.

Backed by ARP's reputation as the fastener of choice for professional engine builders worldwide, the 135-3605 head bolt kit represents the quality standard in cylinder head fastening systems.