ARP 124-4004 High Performance Cylinder Head Stud Kit Chrome Moly - 8740

The ARP 124-4004 is a high-performance cylinder head stud kit engineered for demanding applications where reliability and precision are critical. Built from premium grade 8740 chrome moly steel and rated at 200,000 psi tensile strength, these studs deliver exceptional clamping force and durability that exceeds aircraft-quality standards.

Key Features:

• Premium 8740 chrome moly steel construction rated at 200,000 psi tensile strength
• Precision heat-treated vertically in specialized racks for complete and uniform heat penetration
• Centerless ground after heat-treat for exceptional concentricity and straightness
• Thread rolled after heat-treat for approximately 1000% better fatigue strength versus pre-heat-treat threading
• Hex head design for convenient installation and removal
• Includes hardened parallel-ground washers for even load distribution and accurate torque readings
• Undercut shorter studs (where applicable) equalize stretch for more consistent clamping force

Why Choose Head Studs Over Bolts:

• Superior alignment of cylinder heads and gaskets during assembly
• More accurate and consistent torque loading without torsional stress
• Studs stretch only on the vertical axis when torqued, eliminating the twisting forces that bolts experience
• Easier and faster engine assembly, particularly important for racing applications requiring frequent service
• Reduced risk of head gasket failure through optimized clamping characteristics

Installation Notes:

Studs should be installed finger-tight in a relaxed mode—never crank them in using a jammed nut. This allows the stud to stretch properly along the vertical axis when torque is applied to the nut. Always re-torque after initial engine run-in to compensate for head gasket compression.

ARP's manufacturing process ensures that each stud meets strict quality standards with zero defects and zero failures. The precision tolerances mean gaskets and cylinder heads will align perfectly and glide smoothly into position during assembly. Each stud is stamped with the ARP logo as your assurance of quality and authenticity.