Upgraded conical spring kit for the 2001-2016 GM 6.6L Duramax. The conical valve springs with higher spring rate and the lighter weight of valve train components result in sharper response and eliminate valve float under high engine RPMs. These stiffer springs have an installed pressure of 125 pounds and handle 60+ psi of boost.

The spring retainers and seats are made of high-strength chromoly steel to handle the increased spring pressure. The FKM valve seals are tailored to the Cast Iron Heads’ valve guides for a tight seal.

Each kit services two complete cylinder heads.

Kit Includes:

• 32 springs
• 32 spring retainers
• 32 spring seats
• 32 sets of keepers