ARP 234-5501 Main Cap Stud Kit Chrome Moly Steel

ARP's main cap stud kit provides critical upgrades for high-performance engine builds, eliminating main cap walk and fretting while protecting engine block threads. Each stud is precision-manufactured from 8740 chrome moly steel and heat-treated to an impressive 200,000 psi tensile strength—significantly stronger than Grade 8 hardware. The kit includes hardened parallel-ground washers and aerospace-quality nuts for complete installation.

Key Features:

• 8740 chrome moly steel construction heat-treated to 200,000 psi tensile strength
• J-form threads rolled after heat-treat for threads 1000% stronger than conventional fasteners
• Studs provide more accurate torque readings by eliminating twisting forces during installation
• Reduces stress on engine block threads, extending block life especially on aluminum engines
• Simplifies engine assembly with proper main cap alignment every time
• Complete kit with hardened parallel-ground washers and aerospace-quality nuts
• Exceeds stringent aerospace specifications for professional engine building

ARP recommends main studs over main bolts for several technical advantages: studs maintain all clamping forces on a single axis without twisting into the block, allowing for more precise torque specifications and reducing thread wear. This makes them the preferred choice for professional engine builders and serious performance enthusiasts.