ARP 255-3701 Pro Series Cylinder Head Bolt Kit - 12-Point ARP2000

The ARP 255-3701 Pro Series cylinder head bolt kit delivers professional-grade clamping force and reliability for high-performance and competition engines. Engineered with ARP2000 material rated at 200,000 psi tensile strength, these fasteners exceed the strength of standard Grade 8 bolts by a significant margin.

Key Features:

• ARP2000 alloy construction rated at 200,000 psi for superior strength
• 12-point head design for precise torque application
• Cold-forged construction ensures molecular integrity
• Heat-treated prior to thread rolling for exceptional fatigue resistance
• Thread rolled after heat-treat for approximately 10 times better fatigue strength
• Centerless ground for exceptional concentricity and precise alignment
• Wide-area flanged head eliminates need for valve train removal during retorquing
• Undercut short bolts provide optimized stretch characteristics to prevent head gasket failure
• Hardened parallel-ground washers included for even load distribution

Why Choose ARP Pro Series:

ARP's precision manufacturing process sets these fasteners apart. Each bolt is vertically rack heat-treated to ensure complete penetration and uniform properties throughout. The centerless grinding process involves multiple precision cuts, resulting in exceptional straightness that allows cylinder heads and gaskets to glide into perfect alignment during assembly.

The reduced wrenching hex with wide-area flange design permits cylinder head service without removing valve train components, and accommodates larger diameter valve springs common in performance applications. Thread rolling after heat-treat—though more expensive and demanding on tooling—produces vastly superior fatigue resistance compared to pre-heat-treat threading methods used by other manufacturers.

Every ARP fastener is manufactured to meet the company's zero-defect, zero-failure quality standard, making these the preferred choice of professional engine builders across all forms of motorsports.