12v Cummins – Conical Valve Spring Kit

Manton Heavy Duty 12v Conical Springs, Billet Retainers & Lock Kit For the 1989-98 12v 5.9L engines. Includes : (12) Conical Valve Springs (12) Billet Steel Retainers (24) Valve Locks Spring Specs: 170lb seat pressure at 1.940 installed height / 375lbs. at 1.275 open height Coil binds 1.225  ( max valve lift accommodation of .650 if installed @ 1.940) Designed for up-to 6,500rpm safe for daily driving & race capable If your running over 40psi & 3700rpm, this is one of the kits for you. Other options available too. Stronger pushrods are recommended when running this kit. Upgrade your 12V 5.9L engine with Manton Heavy Duty Conical Springs, Billet Retainers & Lock Kit. Ideal for engines running over 40psi and 3,700rpm; stronger pushrods recommended for this setup. Protects valves from being pushed open under high boost conditions, enhancing efficiency and longevity. Engineered for high boost capability and maximum valve train stability. Perfect for stock rebuilds or high-performance race applications. Lightweight 7-degree billet steel retainers designed to match conical spring shape, stronger than OEM. Includes 7-degree valve locks designed for these retainers. Heat-treated spring shims available in various thicknesses for adjusting seat pressure to accommodate max boost.