ARP 135-3707 High Performance Cylinder Head Bolt Kit Chrome Moly - 8740 12-Point

The ARP 135-3707 High Performance Series cylinder head bolt kit delivers professional-grade fastening strength for demanding engine builds. Manufactured from premium 8740 chrome moly steel and heat-treated to 180,000 psi—15% stronger than Grade 8—these fasteners provide exceptional clamping force and reliability for high-performance applications.

Key Features:

• Premium 8740 chrome moly steel construction rated at 180,000 psi tensile strength
• 12-point head design with wide-area flange for secure wrenching and even load distribution
• Cold-forged manufacturing ensures molecular integrity and superior fatigue resistance
• Heat-treated prior to thread rolling for maximum strength and durability
• Thread rolled after heat treatment for approximately 10 times better fatigue life
• Centerless ground for exceptional straightness and precise cylinder head alignment
• Includes hardened parallel-ground washers for accurate torque readings and even load distribution
• Wide-area flanged head design eliminates need for valve train removal during retorquing
• Undercut short bolts (where applicable) provide optimized stretch to prevent head gasket failures

Manufacturing Excellence:

ARP's vertical rack heat-treating process ensures complete and uniform heat penetration throughout each fastener, delivering consistent material properties that inferior basket-treated fasteners cannot match. The centerless grinding process involves multiple precision cuts to produce exceptionally straight bolts that allow cylinder heads and gaskets to align perfectly during assembly.

Installation Notes:

These head bolts provide more accurate and consistent torque loading compared to standard fasteners. Always re-torque after initial engine operation to compensate for head gasket compression. The included hardened washers must be used to ensure proper load distribution and accurate torque measurements.

ARP High Performance Series head bolts are engineered for both serious street performance and competition applications where reliability and consistent clamping force are critical. Each fastener is stamped with the ARP logo as your assurance of quality and is backed by ARP's zero-defect quality standard.