Fits: 2001 thru 2022 Chevy Silverado/GMC Sierra 2500HD/3500HD LB7/LLY/LBZ/LMM/LML/L5P Duramax Diesel 

Manton is proud to present a premium valve spring assembly for the 6.6L Duramax engine platforms. This valve spring system has been engineered to work in unison with all its included components to provide optimal valvetrain stability.

We designed this spring package to be versatile, suitable for both stock rebuilds and purpose-built engines. Our engineering team carefully evaluated what was needed to create a true performance, race-quality spring package. We aimed for higher boost capability, improved spring shape, and increased RPM capacity.

The new spring shape ensures maximum stability at high RPM while reducing wire stress, thus increasing service life even in low RPM applications. We have increased the valve spring seat pressure to 130 lbs to maintain valve control under higher boost conditions. Our package includes lightweight billet steel retainers designed to mate perfectly with the conical spring shape. These retainers are lighter and stronger than OEM retainers due to their reduced size. Additionally, valve locks are included to pair with the new retainers.

Overall, we have developed a spring package that offers maximum capability while remaining a complete drop-in upgrade.

Features: 

• Engineered for overall valvetrain stability

• Designed for higher boost capability

• Improved spring shape for maximum stability at high RPM

• Increased service life, even in low RPM applications

• Valve spring seat pressure increased to 130 lbs

• Lightweight Billet steel retainers designed for conical spring shape

• Stronger and lighter retainers compared to OEM

• Drop-in upgrade for ease of installation

Includes:

• (32) Conical Valve Spring Set

• (32) Billet Steel Retainer Set

• (32) Chromoly Spring Seat Set

• (64) Valve Lock Set

Notes:

• L5P fitment read notes below

• If you are installing this kit on a L5P, you won't be using the spring cups. The valve stem seals act as a cup to keep the spring positioned from moving around.