ARP 247-4203 Cylinder Head Stud Kit Pro Series - 12-Point

The ARP 247-4203 Pro Series head stud kit delivers championship-proven performance for high-performance and racing engines. Engineered with ARP's premium 8740 chrome moly steel alloy and precision manufacturing processes, these studs provide superior clamping force and reliability under extreme conditions.

Premium Construction and Heat Treatment:

• Premium grade 8740 chrome moly steel rated at 200,000 psi tensile strength
• Vertical rack heat-treatment ensures complete and uniform heat penetration
• Thread rolling performed after heat-treat for 1000% better fatigue strength
• Centerless ground to exacting tolerances for perfect concentricity
• 12-point head design for precise torque application

Performance Advantages:

• Studs provide more accurate and consistent torque loading versus bolts
• Eliminates twisting forces during installation for uniform clamping
• Specially undercut short studs equalize stretch for more consistent head gasket sealing
• Superior alignment allows cylinder heads and gaskets to glide into position
• Hardened parallel-ground washers included for even load distribution

Why Choose Studs Over Bolts:

Head studs are the preferred choice for racing and high-performance applications where frequent engine service is required. Unlike bolts which experience both torsional and tensile stress during installation, studs stretch only on the vertical axis when torqued, providing more predictable and reliable clamping force. Studs should be installed finger-tight in a relaxed mode, never cranked in with a jammed nut.

Each ARP stud is stamped with the ARP logo as your assurance of quality. This kit includes all necessary studs and hardened washers for a complete installation. Remember to re-torque after initial engine run-in to compensate for head gasket compression.