ARP 234-4315 Cylinder Head Stud Kit Chrome Moly - 8740 12-Point

The ARP 234-4315 is a high-performance cylinder head stud kit engineered for serious engine builders who demand absolute reliability. This Pro Series kit utilizes premium grade 8740 chrome moly steel rated at 200,000 psi—far exceeding aircraft quality standards and 15% stronger than Grade 8 fasteners.

Advanced Manufacturing Process:

• Vertically racked heat treatment ensures complete and uniform heat penetration to 200,000 psi tensile strength
• Centerless ground after heat treat for exceptional concentricity and straightness
• Thread rolled after heat treatment for approximately 1000% better fatigue strength compared to pre-heat-treat threading
• Cold-forged construction maintains molecular integrity throughout the fastener
• Undercut short studs equalize stretch characteristics for consistent clamping force

Key Features:

• 12-point head design with wide-area flange eliminates need for valve train removal during retorquing
• Precision tolerances allow cylinder heads and gaskets to glide into perfect alignment
• Hardened parallel-ground washers included for even load distribution and accurate torque readings
• Each stud stamped with ARP for quality assurance
• Designed to prevent head gasket failures through optimized clamping force and stretch compensation

Installation Advantages:

Studs provide superior accuracy compared to bolts because they stretch only on the vertical axis during torquing, eliminating the twisting forces that affect bolts. Install studs finger-tight in relaxed mode, then apply torque to the nut for consistent, predictable clamping force. The undercut design on shorter studs provides stretch rates similar to longer studs, ensuring even pressure distribution across the head gasket. Always re-torque after initial engine run-in to compensate for gasket compression.

This kit meets ARP's zero-defect, zero-failure quality standard and is the preferred choice of professional engine builders across all forms of racing and high-performance applications.