ARP 125-3601 High Performance Cylinder Head Bolt Kit Chrome Moly - 8740

The ARP 125-3601 High Performance Series cylinder head bolt kit delivers professional-grade strength and reliability 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), these fasteners provide superior clamping force and durability.

Key Features:

• 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
• Cold-forged for molecular integrity and consistent performance
• Heat-treated vertically in precision racks for complete penetration
• Thread rolled after heat-treatment for 10x better fatigue strength
• Centerless ground for exceptional straightness and concentricity
• Includes hardened parallel-ground washers for even load distribution

Manufacturing Excellence:

ARP's precision manufacturing process ensures every fastener meets their zero-defect quality standard. Each bolt is vertically heat-treated to ensure uniform properties throughout, then centerless ground through multiple precision cuts to achieve near-perfect concentricity. This exacting process ensures cylinder heads and gaskets align effortlessly during assembly. The thread rolling process occurs after heat treatment, which significantly improves fatigue resistance compared to pre-heat-treat threading methods used by other manufacturers.

Installation Benefits:

The 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 reduced wrenching hex provides adequate tool engagement while accommodating larger diameter valve springs. Each kit includes hardened parallel-ground washers to ensure accurate torque readings and even clamping force distribution across the cylinder head surface.

Trusted by professional engine builders across all forms of motorsports, ARP fasteners represent the industry standard for high-performance engine assembly. Each component is stamped with the ARP logo as assurance of authentic quality and precision manufacturing.