ARP 234-4338 High Performance Head Stud Kit Chrome Moly - 8740 12-Point

The ARP 234-4338 is a high-performance head stud kit engineered for serious engine builders who demand ultimate reliability and precision. Built from premium 8740 chrome moly steel and rated at 200,000 psi, this Pro Series kit delivers the superior clamping force needed for high-performance and competition applications.

Key Features:

• Premium 8740 chrome moly steel construction rated at 200,000 psi
• 12-point head design for improved wrench engagement
• Precision heat-treated vertically in special racks for complete penetration
• Centerless ground after heat-treat for exceptional concentricity
• Thread rolled after heat-treat for 10x better fatigue strength
• Undercut short studs equalize stretch for consistent clamping force
• Includes hardened parallel-ground washers for even load distribution

Why Choose Studs Over Bolts:

Head studs provide superior accuracy and consistency compared to head bolts. Unlike bolts that experience both torsional and tensile stress during installation, studs stretch only on the vertical axis when torqued. This results in more accurate torque readings and consistent clamping force. Studs also make engine assembly easier by ensuring perfect alignment of cylinder heads and gaskets—critical for racing applications that require frequent servicing.

Manufacturing Excellence:

ARP's precision manufacturing process sets the industry standard. Each stud is cold-forged to ensure molecular integrity, then vertically heat-treated for uniform results. The centerless grinding process involves approximately ten precision cuts to achieve near-perfect concentricity, allowing cylinder heads and gaskets to glide into position with perfect alignment. Thread rolling after heat-treat—though more expensive and demanding on tooling—produces fasteners with dramatically superior fatigue resistance.

The undercut design on shorter studs helps prevent head gasket failures by providing additional stretch to compensate for gasket compression, ensuring optimal engine sealing under extreme conditions. Every ARP stud is stamped with the ARP logo as assurance of uncompromising quality and zero-defect manufacturing standards.

Installation Note: Studs should be installed finger-tight in a relaxed mode—never cranked in using a jammed nut. After initial engine run-in, re-torque all fasteners to compensate for head gasket compression.