Hamilton 07-CC-24V25+ Flat Tappet Conversion Kit - 2025-2026 Ram 6.7L Cummins

The Hamilton 07-CC-24V25+ is a complete flat tappet conversion kit engineered for 2025-2026 Ram 6.7L Cummins engines. Every component - forged steel camshaft, DLC-coated tappets, heavy-duty pushrods, and upgraded rocker arms - is built to work as a matched system, tested across thousands of dyno runs and millions of real-world miles. This is a SEMA-certified, 49-state compliant kit designed for stock and mild builds that prioritize long-term reliability and consistent valve timing.

What Comes In The Kit

This is a complete matched valvetrain system. Every component is included and engineered to work together:

• Forged steel camshaft (178 steel, forged - not cut from bar stock)
• DLC-coated flat tappets (gas carburized, polished, Diamond-Like Carbon coated)
• Heavy-duty pushrods (3,500+ lb buckling force vs approximately 1,800 lb for OEM)
• Upgraded rocker arms (gas carburized ball and foot, DLC-coated trunnion)

Why This Kit Is Different From Weaker Alternatives

Most valvetrain upgrades replace one component at a time. The 07-CC-24V25+ replaces the entire system with matched components designed to work together from the first startup.

Forged camshaft: The 178 steel cam is forged, not cut from bar stock. Forging produces a denser, more uniform grain structure and creates a natural hardness layer on the cam exterior during the forging process - adding durability that machined alternatives cannot replicate.

DLC-coated tappets: Each tappet is gas carburized, polished, and finished with a Diamond-Like Carbon coating. DLC dramatically reduces friction and wear - but the coating requires correct oil viscosity, correct lash, and staying within the RPM ceiling to perform as designed. Details are in the requirements section below.

Heavy-duty pushrods: Rated above 3,500 lb buckling force - nearly double the OEM spec of approximately 1,800 lb. Less deflection under high cylinder pressure means valve timing stays consistent where stock pushrods flex.

Upgraded rocker arms: Gas carburized ball and foot for reduced friction and longer service intervals. DLC-coated trunnion to prevent galling - a common OEM failure point under sustained stress.

Stock and Mild Builds - Know Where This Kit Fits

This kit is SEMA-certified and 49-state compliant. Hamilton describes it as the right choice for stock or mild builds that do not exceed 4,000 RPM and use OEM valve springs.

If your build regularly pushes above 4,000 RPM or runs high-pressure aftermarket valve springs, this kit is not sized for that use case. High RPM amplifies the impact between the cam and tappet. High spring pressures increase load on the DLC coating. The coating is engineered to last within the operating parameters above - running outside them shortens its life. Hamilton is direct about this tradeoff: longevity requires staying within the kit's design boundaries.

Oil and Lash Requirements - These Are Not Optional

• Standard conditions: Valvoline Premium Blue 15W-40 or Schaeffer 700 Series 15W-40
• Sub-zero/winter conditions: Valvoline Premium Blue 5W-40 or Schaeffer 5W-40
• Oil filter: Fleetguard Stratapore LF16035
• Intake valve lash: 0.010 inch
• Exhaust valve lash: 0.020 inch

Verify lash after 5 minutes of running and again after retorquing the head. Any wear metals from other engine failures in the unfiltered splash oil can degrade the DLC coating quickly - address known contamination issues before installing this kit.

Surfaced Head or Block - Call Hamilton Before Ordering

If your engine block or cylinder head has been surfaced, call Hamilton directly before placing your order. Surfacing changes deck height and affects clearance. Hamilton requires verification to confirm proper fitment of the 07-CC-24V25+ in these situations. Do not assume the kit clears - verify first.

Avoid These Common Mistakes

• Using the wrong oil: Emission-compliant oils low in zinc, phosphorous, or molybdenum will not protect the DLC coating. Use only the Hamilton-specified oils listed above.
• Setting incorrect lash: Lash too loose increases impact force when the tappet goes solid. Lash too tight prevents adequate oil film from forming. Set intake at 0.010 inch and exhaust at 0.020 inch, verify after warm-up, and recheck after head retorque.
• Installing on a build that regularly exceeds 4,000 RPM: High RPM breaks down the oil film between the cam and tappet faster than the DLC coating can withstand long-term. This kit is for stock and mild builds within that RPM ceiling.
• Skipping zinc additive at first startup: Add zinc additive before the engine first starts. Do not skip this step.
• Ordering without planning for the core return: The $800 core charge is collected at checkout. You are responsible for return shipping on the core rocker arms. Confirm you have usable cores to return before ordering.
• Ordering after machining without verification: If the head or block has been surfaced, contact Hamilton before ordering. Fitment cannot be assumed after machining.

Before You Order - Confirm These

• Engine is a 2025-2026 Ram 6.7L Cummins
• Pre-order timeline is acceptable - kits ship mid to late April 2025
• $800 core charge is understood and usable core rocker arms are available to return
• Build does not regularly exceed 4,000 RPM and uses OEM valve springs
• Correct oil specification will be used - Valvoline Premium Blue or Schaeffer 15W-40 (5W-40 in winter)
• Head and block have not been surfaced, or Hamilton has been contacted for fitment verification

All six confirmed? The Hamilton 07-CC-24V25+ is the correct kit - a complete matched valvetrain conversion backed by decades of testing, built specifically for the 2025-2026 Ram 6.7L Cummins.

Frequently Asked Questions