ARP 204-4206 Cylinder Head Stud Kit 8740 Chrome Moly 12-Point

The ARP 204-4206 is a professional-grade cylinder head stud kit engineered for high-performance and competition engines. Manufactured from premium 8740 chrome moly steel, these studs are heat-treated to 200,000 psi tensile strength, delivering exceptional clamping force and reliability under extreme conditions.

Key Features:

• 8740 chrome moly steel construction heat-treated to 200,000 psi for superior strength
• 12-point head design with wide area flange for easy retorquing without valve train removal
• Undercut short studs equalize stretch and clamping force to prevent head gasket failure
• Thread rolled after heat-treat for 10x better fatigue strength than pre-treated threading
• Centerless ground for precise concentricity and perfect head/gasket alignment
• Includes hardened parallel-ground washers for even load distribution and accurate torque readings

Why Studs Over Bolts:

Head studs provide superior clamping accuracy because they stretch only on the vertical axis during torquing, unlike bolts which experience both rotational and tensile forces simultaneously. This results in more consistent torque values and better head gasket sealing. Studs also simplify engine assembly by allowing cylinder heads and gaskets to align properly without fighting fastener misalignment.

Installation Notes:

Install studs finger-tight in a relaxed state—never crank them in with a jammed nut. After initial engine run-in, re-torque the nuts to compensate for head gasket compression. The undercut design on shorter studs ensures even clamping force across the entire head surface.

Every ARP stud is stamped with the ARP logo as your assurance of zero-defect, zero-failure quality standards trusted by professional engine builders worldwide.