ARP 140-5401 Main Stud Kit Chrome Moly Steel - 8740

ARP 140-5401 main stud kit provides superior engine block fastening over conventional main bolts, delivering critical benefits for high-performance and precision engine builds. These studs eliminate main cap walk and fretting while protecting valuable engine block threads from damage during assembly and disassembly.

Key Features:

• Manufactured from premium 8740 chrome moly steel with heat treatment to 200,000 PSI tensile strength
• J-form threads rolled after heat-treat for 1000% greater thread strength compared to cut threads
• Studs provide more accurate torque readings than bolts by eliminating torsional twist during installation
• All clamping forces applied on a single axis, reducing stress on engine block threads
• Simplifies engine assembly and ensures proper main cap alignment every time
• Includes hardened parallel-ground washers and aerospace-quality nuts
• Exceeds stringent aerospace fastener specifications

ARP main studs are the preferred choice of professional engine builders for competition and high-performance applications. The stud design allows the fastener to be installed and properly torqued without the rotational forces that bolts create, resulting in more consistent clamping loads and extended engine block life—particularly critical for aluminum block applications.