ARP 135-4301 Head Stud Kit High Performance Series - 8740 12-Point

The ARP 135-4301 is a premium high-performance head stud kit engineered for serious competition and high-stress applications. Built with ARP's renowned 8740 chrome moly steel alloy and featuring 12-point heads, this kit delivers the exceptional strength and reliability that professional engine builders demand.

Premium Manufacturing Process:

• Constructed from 8740 chrome moly steel rated at 200,000 psi tensile strength
• Vertical rack heat-treatment ensures complete and consistent heat penetration throughout each stud
• Centerless ground to exacting tolerances for near-perfect concentricity and straightness
• Thread rolled after heat-treatment for 1000% better fatigue strength compared to pre-heat-treat threading
• Cold-forged construction maintains molecular integrity

Key Features and Benefits:

• 12-point head design with wide-area flange eliminates need for valve train removal during cylinder head retorquing
• Specially undercut shorter studs equalize stretch for more consistent clamping force
• Precision tolerances allow gaskets and cylinder heads to align perfectly during assembly
• Hardened parallel-ground washers included for even load distribution and accurate torque readings
• Superior clamping consistency helps prevent blown head gaskets

Why Studs Over Bolts:

Head studs provide superior performance compared to bolts because they stretch only along the vertical axis when torqued, eliminating the twisting force that bolts experience. This results in more accurate and consistent torque loading. Studs also simplify engine assembly by ensuring proper alignment of the cylinder head and gasket. For racing and high-performance applications where frequent disassembly is required, studs offer significant advantages in both reliability and ease of service.

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

ARP's Pro Series head studs represent the industry standard for competition engine building, trusted by top professional builders across all forms of motorsports. Each stud is stamped with the ARP logo as your assurance of zero-defect, zero-failure quality.