ARP 145-4201 Cylinder Head Stud Kit Chrome Moly - 8740 12-Point

The ARP 145-4201 is a premium cylinder head stud kit engineered for high-performance and competition engines. Built from ARP's 8740 chrome moly alloy steel and heat-treated to 200,000 psi, these studs deliver exceptional strength and reliability that professional engine builders trust for their most demanding applications.

Key Features:

• Premium 8740 chrome moly steel construction rated at 200,000 psi tensile strength
• 12-point head design for precise torque application and easy installation
• Vertical rack heat-treatment ensures complete and consistent heat penetration throughout each stud
• Centerless ground after heat-treat for superior concentricity and straightness
• Thread rolled after heat-treatment for 10x better fatigue strength compared to pre-heat-treat threading
• Undercut short studs equalize stretch for more consistent clamping force
• Includes hardened, parallel-ground washers for even load distribution and accurate torque readings

Why Choose Studs Over Bolts:

Head studs provide superior clamping accuracy compared to bolts because they stretch only along the vertical axis when torqued, eliminating the twisting forces that bolts experience. This results in more consistent torque loading and better head gasket sealing. Studs also simplify engine assembly by ensuring perfect alignment of cylinder heads and gaskets—components literally glide into position thanks to ARP's exacting manufacturing tolerances.

Installation Notes:

Install studs finger-tight in a relaxed mode—never crank them in with a jammed nut. Apply torque only to the nut, allowing the stud to stretch uniformly. Always re-torque after initial engine run-in to compensate for head gasket compression.

ARP's precision manufacturing process and zero-defect quality standard make these head studs the choice of professional engine builders across all forms of motorsports. Each stud is marked with the ARP stamp as your assurance of uncompromising quality.