The ARP 147-2503 Harmonic Balancer Bolt Kit is designed to securely retain the harmonic damper on 2007.5–2018 6.7L Cummins diesel engines, delivering the clamping force needed to handle torsional loads and prevent loosening under stress. Built with ARP’s high-strength fastener technology, this kit includes premium bolts and washers to provide increased durability and consistent clamping over factory hardware for reliable performance in demanding diesel application