2019-2024 6.7 Cummins Flat Tappet Conversion Kit™

2019-2024 Ram 6.7L Cummins Flat Tappet Conversion Kit™

This complete kit replaces the failure-prone factory hydraulic roller lifters and camshaft in your 2019-2024 Ram 6.7L Cummins with Hamilton’s proven flat tappet design — removing the OEM roller-bearing failure point at the source. It runs on factory calibration with no tune required, keeps all emissions equipment in place, and is SEMA-certified for 49-state street use. Owners report quicker spool, sharper throttle response, lower EGTs, and fuel economy gains on otherwise stock trucks.

“Innovation slightly faster than imitation.”

What’s in the kit

• Forged 178/208 efficiency camshaft
• DLC-coated steel tappets
• Heavy-duty upgraded pushrods
• Adjustable rocker arms with DLC-coated trunnions and upgraded oiling

Why it’s built to last

Forged steel camshaft. Our 178/208 cams are forged, not cut from bar stock — producing a denser, more uniform grain structure. A natural “halo” forms on the exterior during forging, adding strength for extended service life.

DLC-coated tappets. Each tappet is gas carburized and polished to create a hard, stable base for the Diamond-Like Carbon (DLC) coating — an ultra-hard surface finish that dramatically reduces friction and wear.

Heavy-duty pushrods. Rated at 3,500+ lbs buckling force versus roughly 1,800 lbs for OEM, they drastically reduce deflection at high cylinder pressures and keep valve timing precisely in sync under load.

Upgraded rocker arms. High-quality casting built for intense heat cycles, with a gas-carburized ball and foot to reduce friction, and a DLC-coated trunnion that minimizes the galling common to OEM trunnions.

Fitment

• 2019-2024 Ram 2500, 3500, 4500, and 5500 with the 6.7L Cummins
• Delivery address must be outside California (we’re confident it would pass CARB, but we don’t do business in California)
• If your engine block or cylinder head has been surfaced, call us to verify fitment before ordering

Requirements & Care (read before installing)

This is an emissions-compliant performance camshaft — think of it as the permanent fix for stock or mild builds that stay under 4,000 rpm on OEM springs. Follow these requirements to keep your warranty valid and your DLC coating healthy.

Approved oil — required. Use a 15W-40 (or 5W-40 in sub-zero conditions) with adequate zinc, phosphorus, and molybdenum. Thin or low-additive oils don’t provide the shear strength a flat tappet needs. Approved oils:

• Valvoline Premium Blue 15W-40
• Valvoline Synthetic Blend 15W-40
• Schaeffer 15W-40 (700 Series)
• Rotella T5 15W-40
• Rotella T6 15W-40

Preferred filter: Fleetguard Stratapore LF16035. Running a non-approved oil voids the warranty. All warranty claims must include the failed parts and an oil sample.

Valve lash — set it correctly. Intake 0.010″ / exhaust 0.020″, set after 5 minutes of running, then re-checked after you retorque the head. Lash that’s too loose increases impact when it goes solid; too tight prevents the oil film from forming before the next impact cycle — either extreme damages the coating.

Keep it in its happy zone. High rpm (above 4,000) and high spring pressures break through the oil film and degrade the DLC into graphite over time. Emissions-compliant oils don’t carry enough additive package for those extremes. You can chase longevity or chase big power on this setup — not both for long. Note that wear metals from any other failure circulate in the unfiltered splash oil between the cam and lifters and can kill the coating quickly, so address any existing issues first.

Proven performance & reliability

Hamilton cams have powered countless diesel engines for millions of road miles and thousands of dyno runs. When you choose Hamilton Cams, you’re buying direct from the manufacturer — proven innovation, superior craftsmanship, and a kit engineered to deliver reliable power for the long haul.

2019-2024 6.7 Cummins Flat Tappet Conversion Kit — FAQ

Will this fix the 2019+ Cummins lifter tick and cam failure?

Yes. The factory hydraulic roller lifter relies on a needle-bearing roller wheel that can degrade, score the cam lobe, and contaminate the oil. This kit removes the roller assembly entirely and replaces it with DLC-coated flat tappets that have no bearing to fail.

Does it require a tune or programmer?

No. The 178/208 cam profile is designed to run on factory calibration. No aftermarket tuner is needed and all factory emissions equipment stays in place.

Does it include the camshaft, or do I buy that separately?

Everything is included: the forged 178/208 camshaft, DLC-coated steel tappets, heavy-duty pushrods, and adjustable rocker arms with DLC-coated trunnions. No separate cam purchase is required.

What oil do I have to run?

A 15W-40 (or 5W-40 in sub-zero conditions) with adequate zinc, phosphorus, and molybdenum. Approved oils include Valvoline Premium Blue 15W-40, Schaeffer 15W-40, and Rotella T5/T6 15W-40. The Fleetguard LF16035 is the preferred filter. Running a thin or low-additive oil voids the warranty.

Do I need the special Mopar lifter tool?

No. The expensive Mopar tool is only required to install the factory-style roller lifters. Flat tappet lifters do not need it, which makes this conversion simpler to install in-frame.

Which trucks does it fit?

2019-2024 Ram 2500, 3500, 4500, and 5500 trucks with the 6.7L Cummins and hydraulic roller lifters. Delivery address must be outside California. If your block or head has been surfaced, call to verify fitment before ordering.

Qualified Installers

Prefer a professional install? These shops are experienced with the Hamilton flat tappet conversion:

• DNR Customs — Wales, MI
• RB Diesel — Bertram, TX
• Unrivaled Diesel — Weatherford, TX
• PowerHouse Machining — Edmonton, AB
• Obsessive Compulsive Diesel — Edmonton, AB
• Central Florida Diesel — Cocoa West, FL
• Point Blank Performance — Jonesboro, AR
• Crustin’s Diesel — Bertram, TX
• Armor Inc. Diesel — Red Deer, AB
• Duernberger Diesel Service — Iron Ridge, WI
• Diesel Works — Fort Worth, TX
• Killer Diesel — Mooreland, IN
• Pure Diesel Power — Marshfield, WI
• S&K Transmission — Phoenix, AZ
• Sin City Diesel — Las Vegas, NV
• Pro Automotive & Diesel — Scappoose, OR
• Tonkin Hillsboro Ram/Dodge — Portland, OR