The ARP 247-5405 Main Stud Kit is designed to strengthen the bottom end of 2007.5–2018 6.7L Cummins engines equipped with a factory girdle, providing the clamping force needed to keep main caps securely in place under high load and increased cylinder pressure. Manufactured from high-strength 8740 chromoly, these studs help reduce main cap walk, protect block threads, and deliver consistent clamping for improved durability and reliability in demanding diesel applications.