Ram 3500 6.4 HEMI Horsepower by Year: Full Specs 2026

The 6.4L HEMI V8 in the Ram 3500 makes 410 horsepower and 429 lb-ft of torque in pickup configuration for the 2014 through 2024 model years. Ram revised that rating to 405 horsepower for the 2025 and 2026 model years, while torque stayed at 429 lb-ft. Cab chassis versions of the same engine are governed lower, at 370 horsepower, because of a lower maximum engine speed built into the calibration.

Those numbers only tell part of the story. The rating changes by model year, and it changes again depending on whether the truck is a pickup or a cab chassis. Here is the full breakdown, year by year and configuration by configuration, along with how this engine’s output stacks up against the diesel option and what real 3500 owners see once mods enter the picture.

Ram 3500 6.4 HEMI Horsepower and Torque by Year 2014 to 2026

The 6.4L HEMI launched in the Ram 2500 and 3500 for the 2014 model year as a step up from the 5.7L HEMI, positioned below the 6.7L Cummins Turbo Diesel. Output stayed flat for a decade before Ram’s mid cycle refresh adjusted the figures for 2025.

The 5 horsepower drop for 2025 lines up with Ram’s broader Heavy Duty refresh, which brought emissions calibration updates and the switch to the 8-speed TorqueFlite HD transmission. Torque output was left unchanged at 429 lb-ft across every model year of production, which is the more relevant number for a truck built to haul and tow rather than sprint.

The 6.4L HEMI is a naturally aspirated 392 cubic inch V8, based on the 5.7L HEMI’s architecture but not sharing its bore or stroke. It uses Variable Valve Timing and cylinder deactivation for highway efficiency, and Ram’s official Heavy Duty engine performance pages confirm the same specification pattern across the 2023, 2025, and 2026 model years for the 3500 pickup.

For the complete engine profile beyond horsepower, including oil type, maintenance intervals, and reliability data, see our Ram 6.4 HEMI specs guide.

Pickup vs Cab Chassis Horsepower Difference in the Ram 3500

Not every 6.4L HEMI in a Ram 3500 makes the same power. Pickup models are rated at 410 hp through 2024 and 405 hp from 2025 onward. Cab chassis versions, which include the 3500 chassis cab used for dump beds, flatbeds, and service bodies, are rated at 370 hp.

The difference comes from a lower governed engine speed rather than a smaller engine or different internals. Ram calibrates the cab chassis version to protect the drivetrain under sustained, heavy commercial loads at higher gross vehicle weight ratings, where a truck might run at high RPM for extended periods rather than in short highway bursts.

Transmission pairing also shifts by configuration. Pickup models built before 2025 use the 66RFE 6-speed automatic or the heavier duty Aisin automatic depending on GVWR, while 2025 and later pickups moved to the 8-speed TorqueFlite HD. Cab chassis trucks continue to run the 66RFE or the Aisin AS69RC 6-speed automatic regardless of model year.

How the 6.4 HEMI Horsepower Compares to the 6.7 Cummins

Buyers cross-shopping the Ram 3500 usually put the 6.4L HEMI up against the 6.7L Cummins Turbo Diesel, and the gap is significant. The 6.7L Cummins makes up to 430 hp and 1,075 lb-ft of torque in current model years, more than double the HEMI’s torque output.

The HEMI still has real advantages. It weighs less than the diesel, which can translate into a higher payload rating on certain configurations, and it costs less to buy and maintain since it skips the DEF system, DPF, and EGR components that add complexity to the Cummins. For buyers who don’t need maximum towing numbers, the 6.4L HEMI’s lower purchase price and simpler service schedule make it a reasonable trade against the Cummins’ torque advantage.

Owners looking to close some of that power gap without switching engines often start with bolt-on mods rather than forced induction. Our 6.4 HEMI MDS delete kit guide covers one of the more common starting points for HEMI owners chasing more consistent power delivery.

Real World Horsepower Ram 3500 Owners Report

Factory ratings are measured at the crankshaft, not at the wheels, and Ram 3500 owners on forums like RamForum.com have run their own dyno tests to see what actually reaches the ground. Wheel dyno results always come in lower than the factory crank rating because of drivetrain loss through the transmission, transfer case, and differential.

One owner with a modified 2015 to 2019 generation 6.4L HEMI, running aftermarket long tube headers, a cat-back exhaust, a performance tune, and an intake modification, recorded 365 rear-wheel horsepower and 382 lb-ft of torque on a mobile dyno in hot outdoor conditions. That truck was already modified, so it does not represent a stock baseline, but it illustrates that the 6.4L HEMI holds a flat, usable torque curve that owners describe as stronger in real driving than most EcoBoost or comparable gas competitors.

Ram forum threads discussing SAE J1349 certified engine data for the 2014 model year 6.4L HEMI note that Chrysler’s certified power figures are based on standardized testing conditions, and several posters report their trucks feel like they make more than the advertised rating once accounting for typical automatic transmission drivetrain loss. This is anecdotal rather than an official measurement, so treat it as context rather than a verified spec.

For a full list of the 6.4L HEMI’s documented mechanical issues by model year, see our Ram 6.4 HEMI problems guide.

How 6.4 HEMI Horsepower Affects Ram 3500 Towing and Payload

Horsepower numbers only matter in the context of what they let the truck actually do. A Ram 3500 with the 6.4L HEMI carries a max payload of 7,590 to 7,680 lbs depending on model year and configuration, and a max conventional towing rating of 18,150 to 18,210 lbs.

Those figures come directly from Ram’s official Heavy Duty towing and engine performance pages and will vary based on cab size, bed length, axle ratio, and single rear wheel versus dual rear wheel setup. For the full year-by-year towing breakdown across every 3500 configuration, see our Ram 3500 towing capacity charts.

Frequently Asked Questions About Ram 3500 6.4 HEMI Horsepower

How much horsepower does a Ram 3500 6.4 HEMI have?

The Ram 3500 pickup with the 6.4L HEMI makes 410 horsepower and 429 lb-ft of torque for the 2014 through 2024 model years, and 405 horsepower with the same 429 lb-ft of torque for 2025 and 2026.

Did the Ram 3500 6.4 HEMI horsepower change for 2025?

Yes. Ram lowered the rating from 410 hp to 405 hp as part of the 2025 Heavy Duty refresh, which also introduced the 8-speed TorqueFlite HD transmission. Torque stayed at 429 lb-ft.

Is the 6.4 HEMI weaker in a Ram 3500 cab chassis?

Yes. Cab chassis versions are rated at 370 hp across all model years, lower than the pickup’s 405 to 410 hp, because of a reduced governed engine speed built into the commercial calibration.

How does the 6.4 HEMI compare to the 6.7 Cummins in horsepower?

The 6.7L Cummins makes up to 430 hp and 1,075 lb-ft of torque, well ahead of the HEMI’s torque figure, though the HEMI offers a lighter engine and lower purchase and maintenance cost.

What transmission comes with the Ram 3500 6.4 HEMI?

Pickup models from 2014 to 2024 use the 66RFE 6-speed or Aisin HD automatic. 2025 and later pickups use the 8-speed TorqueFlite HD. Cab chassis trucks use the 66RFE or Aisin AS69RC 6-speed automatic regardless of year.