Manton-01-16 GM 6.6L Duramax Manton Pressure Tower Valve Spring Kit

The Manton D-105-KIT-Dmax Conical Valve Spring Kit is a complete valvetrain upgrade for the 2001-2022 GM 6.6L Duramax covering LB7 through L5P generations. The kit includes 32 conical valve springs, 32 billet steel retainers, 32 chromoly spring cups, and 64 valve locks - a full 32-valve engine set. Engineered for high boost and increased RPM capability from stock rebuilds to race setups, these springs deliver 130 lbs seat pressure to hold valves closed under elevated cylinder pressures. L5P owners: the spring cups are not used on your engine - valve stem seals serve that function - but the springs, retainers, and locks are correct for L5P fitment.

One Kit Across All Duramax Generations - With One Exception

The D-105-KIT-Dmax covers the full 6.6L Duramax family from the 2001 LB7 through the 2022 L5P. The springs, retainers, and locks are correct for all generations. The spring cups are the one variable: on LB7 through LML engines, the included chromoly cups are installed as part of the spring assembly. On the L5P, the valve stem seals already function as cups to locate the spring - the included spring cups are not installed on L5P engines.

This is not a fitment problem. The kit is correct for L5P - you simply set the 32 spring cups aside. Everything else installs as normal. If your Duramax is an L5P and you were about to order a different part number because of this note, the D-105-KIT-Dmax is still the right kit to order. Confirm your generation, verify your cam lift, and this is the correct spring kit for your build.

What Comes in the Kit

The D-105-KIT-Dmax ships with all four components for a complete 32-valve spring conversion on the 6.6L Duramax.

• (32) Manton Conical Valve Springs - 130 lbs seat pressure, optimized conical shape for high-RPM stability and reduced wire stress
• (32) Billet Steel Retainers - lightweight, matched to conical spring shape, stronger than OEM retainers
• (32) Chromoly Spring Cups - for LB7 through LML engines; not installed on L5P (valve stem seals serve this function on L5P)
• (64) Valve Locks - matched to the included retainers

The core spring conversion - springs, retainers, cups (LB7-LML), and locks - requires no additional sourcing. Shims are a separate decision based on your specific boost level and build goals.

D-105-KIT-Dmax Specs

Confirm the specs and kit contents below match your engine generation, cam lift, and build goals before ordering.

If your Duramax generation, cam lift, and boost level fall within the specs above, this is the correct kit to order for your 6.6L build.

Complete the Duramax Valvetrain Upgrade

Pair this kit with the correct Manton pushrod upgrade for a more complete 6.6L Duramax valvetrain build.

• Manton Series 3 Pushrods - 01-17 GM 6.6L Duramax - chromoly pushrod upgrade to pair with the new spring kit
• Manton Pressure Tower Valve Spring Kit - 01-16 GM 6.6L Duramax - alternative pressure tower spring kit for the Duramax

Avoid These Common Ordering Mistakes

• Skipping the L5P spring cup note - the 32 spring cups are included but not installed on L5P engines; do not let that stop you from ordering the correct kit
• Ordering if your cam lift exceeds .500" - verify your cam lift falls within the .500" max valve lift accommodation before ordering
• Assuming shims are included - heat-treated seat pressure shims are available separately; contact Pure Diesel Power if your boost level requires additional seat pressure adjustment
• Using non-matched retainers with these conical springs - the included billet steel retainers are shaped for the conical spring geometry and are not interchangeable with standard straight-spring retainers
• Placing an order with a California or Colorado shipping address - eligible out-of-state address required

Ready to Order - Confirm These First

• Engine is 2001-2022 GM 6.6L Duramax (LB7, LLY, LBZ, LMM, LML, or L5P)
• Cam lift is at or under .500" max valve lift accommodation
• L5P generation confirmed - spring cups not installed, set them aside
• Shim need assessed - contact Pure Diesel Power if boost requires seat pressure adjustment above base spec
• Eligible (non-California, non-Colorado) shipping address confirmed

For a 2001-2022 6.6L Duramax build at any performance level from a stock rebuild to a race setup, the Manton D-105-KIT-Dmax is the correct conical valve spring kit to order. Verify your generation and cam lift, then add to cart.

Frequently Asked Questions