6.7 Cummins Engine for Sale | OEM Used Cummins ISB 6.7L Inline-6 Turbocharged Diesel for Dodge / Ram 2500, 3500, 4500, 5500

Description

About the 6.7 Cummins Engine

Looking for a used 6.7 Cummins engine for sale? Look no further than the robust power and reliability of this renowned inline-six turbocharged diesel engine from Cummins Inc. Whether you are replacing a worn engine in your Ram 2500, 3500, 4500, or 5500 heavy-duty truck, completing a Freightliner Business Class M2 service rebuild, or sourcing a powerplant for a custom diesel swap project, the 6.7 Cummins is the heart of Dodge and Ram heavy-duty diesel pickup performance since mid-year 2007. Built to handle heavy loads, demanding work cycles, and the punishment of commercial duty cycles, this engine is a favorite among diesel truck enthusiasts, fleet managers, and contractors alike.

Engine Overview: Cummins ISB 6.7L

The 6.7L Cummins ISB turbo diesel engine is renowned for its power output, robust construction, and the legendary durability that has made Cummins B-series engines the choice of Dodge / Ram heavy-duty trucks for decades. Compatible with Dodge Ram 2500 and 3500 (2007.5 through current), Ram 4500 and 5500 chassis cab (2008 through current), and Freightliner Business Class M2 medium-duty trucks, these engines deliver impressive performance across multiple generations. With stock power outputs ranging from 350 horsepower / 610 lb-ft (early 2007.5 to 2010 base trucks) to 420 horsepower / 1,075 lb-ft (current High Output variants), a used 6.7 Cummins engine delivers serious heavy-duty diesel capability.

Critical Buyer Information: The 6.7 Cummins Has Four Distinct Generations

Before ordering, it is essential to understand which generation of the 6.7 Cummins you need. The engine has gone through four distinct generations with significant differences in fuel system, emissions equipment, power output, and reliability characteristics:

Generation 1: 2007.5 to 2012

• Fuel system: Bosch CP3 high-pressure pump (proven reliable design)
• Emissions: DPF + EGR only (NO DEF / SCR system yet)
• Power output: 350 HP / 610 to 800 lb-ft
• Common issues: EGR cooler failures, DPF clogging, CP3 generally reliable
• Years: 2007.5, 2008, 2009, 2010, 2011, 2012 model year Ram 2500 / 3500

Generation 2: 2013 to 2018

• Fuel system: Bosch CP3 high-pressure pump (still reliable)
• Emissions: DPF + EGR + SCR + DEF (Diesel Exhaust Fluid) system added for 2013 plus
• Power output: 350 to 385 HP / 660 to 865 lb-ft (HO variant available)
• Aisin AS69RC transmission paired with HO 385 HP / 865 lb-ft configuration
• Common issues: DEF system sensor failures, otherwise generally reliable
• Years: 2013, 2014, 2015, 2016, 2017, 2018 model year Ram

Generation 3: 2019 to 2023

• Fuel system: Bosch CP4.2 high-pressure pump (NOTORIOUS catastrophic failure history when exposed to fuel contamination or water in fuel)
• Emissions: DPF + EGR + SCR + DEF
• Power output: 370 to 400 HP / 850 to 1,000 lb-ft (HO variant)
• Common issues: CP4.2 fuel pump catastrophic failures can send metal debris through the entire fuel system requiring complete fuel system replacement; aftermarket CP3 conversion kits popular as preventive measure
• Years: 2019, 2020, 2021, 2022, 2023 model year Ram

Generation 4: 2024 to Current

• Fuel system: Current production system
• Emissions: Current EPA / CARB compliant
• Power output: Up to 420 HP / 1,075 lb-ft (HO variant)
• Years: 2024 plus model year Ram

When ordering, match the generation to your truck. Installing a Generation 3 engine (CP4.2) into a Generation 1 truck (designed for CP3) requires fuel system modifications.

Cummins Drivetrain Pairing: The Ram HD Diesel Triangle

The 6.7 Cummins (this listing) is the modern Cummins B-series engine for Ram 2500 / 3500 / 4500 / 5500 heavy-duty trucks. For complete Cummins drivetrain restoration, the 6.7 Cummins pairs with two primary transmission options in our catalog: the Mercedes-Benz G56 6-speed manual transmission (our vaz195 listing, designed and manufactured by Daimler AG with deep 6.29:1 first gear and 0.79:1 sixth overdrive, cast aluminum case 230 lbs, 600 lb-ft stock capacity with reverse synchro, used behind both 5.9 Cummins 2005-2007 and 6.7 Cummins 2007.5-2018 before Ram discontinued the manual option for 2019 plus) is the matched manual transmission option for Cummins-equipped Ram trucks; the Chrysler 48RE 4-speed heavy-duty automatic (our vaz196 listing, 4-speed automatic with overdrive built on the Torqueflite 727 family architecture, 460-475 lb-ft stock capacity, used behind the 5.9 Cummins HPCR 2003-2007 only) is the automatic alternative for the earlier 5.9 Cummins generation, replaced by the 68RFE 6-speed for 2007.5 plus 6.7 Cummins applications. For older Cummins heritage context, the NV4500 (our vaz152 listing, New Venture Gear heavy-duty 5-speed manual at 460 lb-ft for Dodge Ram 2500 1994-2002 / Ram 3500 1994-2005 with Cummins 5.9 12-valve / 24-valve, with fully synchronized 5.61:1 granny low and 0.73:1 overdrive) is the pre-G56 manual transmission heritage for early Cummins applications. Three transmission options across the Cummins B-series timeline: NV4500 for 1994-2005 5.9 Cummins manual; G56 per vaz195 for 2005-2018 5.9 / 6.7 Cummins manual; 48RE per vaz196 for 2003-2007 5.9 Cummins HPCR automatic. The 6.7 Cummins (this listing) pairs with G56 manual (2007.5-2018) or 68RFE / Aisin AS69RC automatic (2007.5 plus).

Why Buy the 6.7 Cummins Engine

• Turbocharged Power: Substantial horsepower and torque output across all generations, ideal for towing heavy trailers, hauling commercial loads, and powering chassis cab work trucks.
• Inline-Six Configuration: Classic Cummins B-series I6 configuration provides excellent torque delivery, smooth power delivery, and the legendary durability that has made Cummins engines the choice of Dodge / Ram heavy-duty trucks for over 30 years (since the original 5.9L 12-valve in 1989).
• Variable Geometry Turbocharger (VGT): Precise boost pressure control across the RPM range, enhancing low-end torque for improved acceleration and towing capability while delivering high-RPM power for highway passing.
• High-Pressure Common Rail (HPCR) Fuel Injection: Delivers fuel at extreme pressures (over 30,000 PSI) for optimized combustion efficiency, reduced emissions, and improved fuel economy versus older mechanical injection systems.
• Cast Iron Block and Head: Built for durability under heavy commercial duty cycles. Many 6.7 Cummins engines exceed 500,000 miles in commercial service with proper maintenance.
• Aftermarket Support: Extensive availability of performance parts, tuners, exhaust systems, intake systems, EGR / DPF delete kits (for off-road and competition use), and aftermarket fuel system upgrades.
• Proven Track Record: Backed by Cummins reputation for reliability and longevity, with the B-series family having powered Dodge / Ram trucks since 1989 (B5.9 12-valve, B5.9 24-valve, then B6.7).
• Smart Diesel Exhaust Fluid (DEF) System (2013 plus): Optimizes DEF consumption for efficient emissions control without compromising engine power. Note: Generation 1 (2007.5 to 2012) engines do NOT have DEF / SCR systems.
• Exhaust Brake (Optional): Integrated exhaust brake helps manage vehicle speed on steep downhill grades, particularly valuable for towing heavy trailers.
• Advanced Cooling System: Engineered to handle sustained heavy-duty operation under high ambient temperatures.

6.7 Cummins Engine Vehicle Applications

Primary Applications: Dodge / Ram Heavy-Duty Pickups

• Dodge Ram 2500 (2007.5 to 2010 with Dodge branding, 2011 to current with Ram branding)
• Dodge Ram 3500 (2007.5 to 2010 Dodge, 2011 to current Ram)
• Ram 2500 (2011 to current)
• Ram 3500 (2011 to current, including HO with Aisin AS69RC transmission)

Chassis Cab Applications:

• Ram 4500 Chassis Cab (2008 to current), medium-duty work truck
• Ram 5500 Chassis Cab (2008 to current), medium-duty work truck

Commercial Truck Applications:

• Freightliner Business Class M2 (medium-duty commercial truck), available with 6.7 Cummins ISB

Important Note: NOT Used in Class 8 Heavy-Duty Trucks

Despite some descriptions claiming compatibility with Freightliner Cascadia, Kenworth T680 / T880, and Peterbilt 567 / 579, the Cummins 6.7L ISB is a medium-duty engine. These Class 8 heavy-duty long-haul trucks typically use the larger Cummins ISX15 / X15 (15-liter) engine, not the 6.7L ISB. The 6.7 Cummins is appropriate for:

• Medium-duty trucks (Class 4 to 7)
• Heavy-duty pickup applications (Ram 2500 / 3500)
• Chassis cab work trucks (Ram 4500 / 5500, Freightliner M2)
• Some recreational vehicle applications (motorhomes, RVs)
• Industrial / agricultural equipment

For Class 8 heavy-duty long-haul applications (Cascadia, T680, 579), you need the Cummins ISX15 / X15. Call (855) 634-4447 to inquire about ISX15 availability.

Emissions Compliance

All our used 6.7 Cummins engines for sale at Part Nests are sold with their original factory emissions equipment intact and adhere to EPA regulations. We include the necessary emissions system components (DPF, EGR system, and where applicable SCR / DEF system for 2013 plus engines) to ensure your truck remains compliant with current standards when properly installed.

Vehicle Compatibility

Why Buy From Part Nests

• Generation correctly identified (avoid receiving wrong generation for your truck)
• Fuel system documented (CP3 vs CP4.2 critical for compatibility)
• Standard Output vs High Output verified
• Donor truck history documented
• All 6 cylinders compression tested before shipping
• VGT turbo function verified
• HPCR injector operation confirmed
• Emissions equipment noted
• Free freight pallet delivery to all 50 states
• 15 day replacement warranty on internal defects
• Cummins B-series experienced support team
• Cross-reference assistance for engine swap projects
• Call (855) 634-4447 to confirm Cummins ISB 6.7L generation (Generation 1 2007.5-2012 with Bosch CP3 high-pressure pump and DPF + EGR only emissions, Generation 2 2013-2018 with Bosch CP3 still reliable plus DEF / SCR added 2013, Generation 3 2019-2023 with Bosch CP4.2 known catastrophic failure history requiring careful inspection, or Generation 4 2024 plus current production), donor vehicle (Dodge / Ram 2500 2007.5-current heavy-duty pickup, Ram 3500 2007.5-current including HO with Aisin AS69RC transmission, Ram 4500 / 5500 Chassis Cab 2008-current medium-duty work truck, or Freightliner Business Class M2 medium-duty commercial truck), fuel system (Bosch CP3 reliable design Gen 1 / Gen 2 vs Bosch CP4.2 with documented catastrophic failure history Gen 3), emissions equipment (DPF + EGR only Gen 1 vs DPF + EGR + SCR + DEF Gen 2 plus), Standard Output vs High Output power rating, VGT turbocharger actuator condition, HPCR injector function (over 30,000 PSI rail pressure), EGR cooler condition (known Gen 1 wear point), and Cummins drivetrain pairing (G56 per vaz195 Mercedes-built manual 2007.5-2018 or 68RFE / Aisin AS69RC automatic 2007.5 plus; older 5.9 Cummins 2005-2007 used G56 too but with different bellhousing per vaz195; 5.9 Cummins HPCR 2003-2007 used 48RE per vaz196 automatic; pre-2005 Cummins used NV4500 per vaz152 manual heritage) before ordering