ARP 256-4001 Cylinder Head Stud Kit Pro Series Chrome Moly - 8740

The ARP 256-4001 Pro Series head stud kit delivers professional-grade engine fastening performance trusted by top engine builders in competition applications. These premium fasteners provide superior clamping force and durability compared to standard head bolts.

Key Features:

• Manufactured from premium 8740 chrome moly steel alloy rated at 200,000 psi tensile strength
• Vertical rack heat-treating ensures complete and uniform heat penetration for consistent strength
• Centerless ground after heat-treat for exceptional concentricity and straightness
• Thread rolled after heat-treatment for 10x better fatigue strength than pre-heat-treat threading
• Hex head design with wide-area flange eliminates need for valve train removal during retorquing
• Undercut shorter 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 performance in most applications by allowing easier engine assembly with assured cylinder head and gasket alignment. Unlike bolts that experience both torsional and tensile forces during installation, studs stretch only on the vertical axis when torqued, resulting in more accurate and consistent clamping force. The undercut design on shorter studs helps prevent head gasket failures by compensating for gasket compression.

Installation:

Install studs finger-tight in a relaxed mode—never force them in using a jammed nut. Apply torque to the nuts according to manufacturer specifications. Re-torque after initial engine run to compensate for head gasket compression.

Each ARP stud is individually stamped with the ARP logo as your assurance of zero-defect, zero-failure quality standards. This kit meets the exacting requirements of professional racing applications while providing reliability for high-performance street engines.