Cummins 6.7L

We offer three kinds of 6.7L Cummins Engine:

Street Series | Tow/Haul Series | Tow/Haul HD Series


DFC Diesel Rebuilders prides itself in being the highest quality product on the market. This is why we can back our engines with a 5 year 160,000km warranty that we stand behind.

Our engines have been re-manufactured to factory specs using all new industry recognized name brand parts that meet and exceed OEM specifications. The block has been professionally machined and bored for use with the next over-sized piston.

All New OEM or equivalent pistons, rings, and gaskets are used to ensure quality and consistency of our engines. Our Re-manufactured Cylinder Heads have all new seats, guides, valves, and stem seals as well as being resurfaced and magnafluxed.

Short Block Engines include:

  • Front cover with seal
  • Rear cover with main seal
  • Oil pan
  • All internal components
  • Complete gasket kit for installation
  • Important installation instructions

Long Block Engine Include:
  • Complete short block assembly and gaskets, plus cylinder head.
  • All rockers/pushrods preset to factory specs.
  • Complete Top End gasket kit
  • ARP Series 2000 Head Studs

All remanufactured engines are serviced with Rottler CNC machining, which guarantees high quality results.

To learn more about Rottler’s innovative, industry leading machines please visit: www.rottlermfg.com


Our Street Series of engines are DFC’s flagship product. Built for work trucks, daily drivers and the diesel enthusiast in mind these engines are a vast improvement from stock as they contain important upgrades to common problem areas. Street Series are Long Blocks with ARP Series 2000 Head Studs.



  • Most comprehensive 5 year / 160,000 km (100,000 mi) warranty in North America.
  • All engines come standard with Total Seal gapless piston rings.
  • Comes assembled with ARP series 2000 head studs.
  • Upgradable to come with an O-ringed cylinder head.
  • Street series, Tow/Haul series and Tow/Haul HD series engines available.
  • Machined with some of the most advanced Rottler machining equipment in North America.
  • Improved gasket sealing methods in common leakage areas.
  • All NEW pistons, rings, bearings, gaskets, seals, valves, springs, hardened seats, stem seals and cast guides standard in every engine.


The DFC Diesel Tow/Haul Series engine comes standard with all the upgrades found in the Street Series model as well as several enhancements to make this engine perfect for towing, hauling and performance applications up to 600 HP. DFC long block assembly including Total Seal gapless piston rings.


Contains all upgrades of the Street Series and includes;

  • DFC long block assembly
  • ARP series 2000 head studs
  • Stage 4 camshaft
  • O-ringed cylinder head
  • 103lb HD valve springs
  • Manton HD push rods
  • Ceramic coated piston crowns and dry film coated skirts
  • Bolt in rear aluminum freeze plug
  • Cometic MLS head gasket set

Built for 600HP
*Rated HP is measured at flywheel same as factory engine HP ratings


The DFC Diesel Tow/Haul HD Series was built for the enthusiast that wants to be capable of up to 850 HP but that will regularly drive on the street and tow trailers between 500 and 750 HP. This model comes equipped with all the features of the Street and Tow/Haul Series but adds a set of Wagler connecting rods, Fluidamper, HD flexplate and balanced rotating assembly.


Includes all the upgrades of the Street Series & Tow/Haul Series as well as includes;

  • Wagler connecting rods
  • Fluidamper
  • HD flexplate
  • Balanced rotating assembly

Built for 850HP
*Rated HP is measured at flywheel same as factory engine HP ratings

DFC can build a very durable and robust combination for your specific needs and all still backed with a 5 year 160,000km (100,000mi) parts and labor warranty. Make us your only choice for Cummins diesel engines in North America.

Tow/Haul and Tow/Haul HD series engines still come backed with a 5 year 160,000 km (100,000 mi) warranty however are considered a severe duty application and require more frequent service intervals as stated in warranty manual supplement for warranty coverage to be considered.


Comes standard with 5 yr 160,000 km (100,000 mi) parts and labor warranty


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Comes standard with ARP Series 2000 head studs


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Cylinder heads fully remanufactured with new SBI valves, springs, cast guides, oversized valve seats and seals


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Cylinder blocks are blueprinted to tighter tolerances than OEM specifications using our Rottler F69 ATC


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Silicone Oil Pan

DFC silicones the oil pans instead of using the factory gasket as they are common to compress and start to sweat prematurely.

ARP Head Studs

Every 6.7 Cummins long block comes standard with ARP Series 2000 head studs preventing premature head gasket failure.

Valve Seats

The factory valve seats were only installed with 0.002”-0.003” crush which can allow them to fall out prematurely causing engine failure. Our engines have oversized SBI valve seats installed with at least 0.008” crush eliminating this from occurring.


DFC installs new valves from MAHLE/Clevite or SBI in every cylinder head we remanufacture. Most companies will re-grind and install used again.

Core criteria

Ensuring every engine is built to the same high quality standards as the next DFC is very strict on what is remanufactured rejecting components that require considerable “restoring” to acceptable specifications.

Weighed Rotating Assemblies

Our production engines are typically matched with near identical weight piston and connecting rod assemblies giving our customers a smoother running and quieter engine.


Front Cover

The front covers on the Cummins engines use a paper gasket that is known to fall inside of the front gear case causing a significant oil loss and expensive repair. By utilizing a high quality silicone we are able to prevent this from occurring.


Our Rottler equipment allows us to remanufacture the Cummins engine to tighter than OEM specifications resulting in a longer lasting more efficient engine assembly.

Valve Springs

Instead of just testing old springs and reusing like most remanufacturers DFC installs brand new SBI valve springs that are still tested for proper spring pressure on every cylinder head we remanufacture.

Cast Guides

Common industry practice is to check guide clearance and if within specification, not replace. DFC considers this practice unacceptable and installs new cast SBI guides in every cylinder head we remanufacture.

Torque specs

These engines use many torque to yield fasteners that require bolt “stretch” to maintain adequate clamp loads. In addition to not just following the OEM procedures for tightening sequence our assembly technicians record the achieved torque load through use of digital torque wrenches ensuring no fastener will come loose over time.