ARP 145-3706 Cylinder Head Bolt Kit 8740 Chrome Moly 12-Point

The ARP 145-3706 is a high-performance cylinder head bolt kit engineered for demanding applications where reliability and consistent clamping force are critical. These fasteners are manufactured from premium 8740 chrome moly steel and precision heat-treated to 180,000 psi tensile strength—approximately 15% stronger than Grade 8 hardware.

Key Features:

• Premium 8740 chrome moly alloy construction for superior strength and durability
• 12-point head design with wide-area flange for secure grip and even load distribution
• Reduced wrenching profile allows cylinder head retorquing without valve train removal
• Cold-forged construction ensures molecular integrity throughout the fastener
• Heat-treated before thread rolling for maximum fatigue resistance
• Thread rolling performed after heat treatment for up to 10 times better fatigue life
• Centerless ground for exceptional straightness and concentricity
• Includes hardened, parallel-ground washers for accurate torque readings and even load distribution
• Select applications feature undercut short bolts to equalize stretch and prevent head gasket failure

ARP's manufacturing process sets the industry standard for head fasteners. Each bolt is placed vertically in precision racks during heat treatment to ensure complete and uniform heat penetration throughout the material. After heat treatment, bolts undergo centerless grinding through approximately ten precise cuts, resulting in exceptional straightness that allows cylinder heads and gaskets to align perfectly during assembly.

The 12-point head configuration with wide-area flange eliminates interference with valve springs and other valve train components, making these bolts ideal for performance engines with upgraded valve train systems. The reduced wrenching hex allows easy access for retorquing procedures without disassembling the valve train—a significant advantage for racing applications requiring frequent maintenance.

These fasteners meet ARP's zero-defect, zero-failure quality standard and are trusted by professional engine builders across all forms of motorsports. Each bolt is marked with the ARP stamp as verification of authenticity and quality. Perfect for high-performance street engines, racing applications, and any build requiring maximum head gasket sealing reliability.

Installation Note: Fasteners should be re-torqued after initial engine run-in to compensate for head gasket compression and ensure optimal clamping force throughout the engine's service life.