Mopar Main Stud Kit - 5.9L 12V Cummins

The ARP Mopar Main Stud Kit for 5.9L 12V Cummins engines (Part No. 247-5402) is a chromoly fastener upgrade designed for high-performance diesel applications where factory main bolts reach their limits. This kit replaces the OEM fasteners with ARP's 12-point chromoly studs and nuts, delivering significantly higher clamping load capacity and superior fatigue resistance. The black oxide finish provides corrosion protection in harsh engine bay environments, critical for diesel engines that operate under sustained high temperatures and cylinder pressures.

The 2-bolt main configuration is specific to the 5.9L 12V Cummins architecture and accommodates the engine block's cast-iron design. Chromoly construction offers approximately 180,000 PSI tensile strength compared to factory steel's lower rating, translating to improved block integrity under boost, nitrous, or compound turbo setups common in Cummins builds. The 12-point nut design engages more surface area on the fastener head, reducing slippage during installation and providing more precise torque values. ARP studs are also reusable across multiple engine builds, unlike single-use factory bolts, making them economical for serious engine work.

This main stud kit is essential for any 5.9L 12V Cummins owner planning power adders, increased fuel injection timing, or extended towing duty under load. Dodge Cummins diesel truck operators, engine builders, and performance shops rely on ARP fasteners to prevent main bearing cap separation—a catastrophic failure mode that can occur when factory hardware proves insufficient. Installation requires correct torque specification and proper sequencing, typically supplied in ARP documentation. The kit ships complete and ready for immediate engine assembly or rebuild work.