Manton 5.9 24V Cummins Conical Valve Spring Kit (D-105-KIT-24v)

Upgrade your 5.9L 24-valve Cummins valvetrain with Manton’s complete Pressure Tower conical valve spring kit. This drop-in package delivers the seat pressure, valvetrain stability, and strength-to-weight advantages needed when running a performance cam, higher boost, or elevated RPM.

Manton’s exclusive conical “Pressure Tower” spring design pairs with ultra-light billet steel retainers to control the valves more effectively than stock cylindrical springs while reducing reciprocating mass. The result is better high-rpm stability, reduced valvetrain stress, and longer component life—whether the truck is a daily driver or a high-boost performance build.

Key Specs

• Seat pressure: 103 lbs @ 1.340″ installed height
• Open pressure: 176 lbs @ 0.920″ lift
• Maximum recommended valve lift: 0.420″ (at 1.340″ installed height)
• Optimized for applications up to approximately 75 psi boost
• Heat-treated spring shims included for fine-tuning seat pressure

Kit Contents

• (24) Conical valve springs
• (24) Ultra-light billet steel valve spring retainers
• (48) Valve locks

Fitment Notes

Designed for 5.9L 24-valve Cummins engines. Also commonly used on 6.7L 24-valve applications.

Important: Some 1998.5–2002 cylinder heads have tighter spring pockets. These may require machining with a valve spring pocket cutter (available separately from Manton) for proper clearance.

This is a complete, ready-to-install package from one of the most trusted names in diesel valvetrain components. Ideal when upgrading cams or increasing boost levels beyond stock.