Duramax LML 6.6-Liter Diesel Engines


The Duramax is a General Motors diesel engine family for light to medium duty trucks, designed by GM and Isuzu. The 6.6-liter Duramax is produced by DMAX, a joint venture between GM and Isuzu in Moraine, Ohio.

SKU: DMX-66LML Category:

6.6L LML Duramax Engines to fit Chevrolet/GMC Pickup Truck from 2011-Current

Engine Identification

To determine the correct part number and configuration available, please gather the VIN (Vehicle Identification Number).


  • Silverado 2500HD, Silverado 3500HD
  • Sierra 2500HD, Sierra 3500HD
  • Kodiak C4500, Kodiak C5500, Kodiak C6500
  • Topkick C4500, Topkick C5500, Topkick C6500

Depending on the model this may be all that is needed.

If you have a C4500, C5500 or C6500, additional information will be needed to determine the correct engine.

  • Assembled in the USA.
  • Blocks and crankshafts are 100% magnaflux tested to avoid cracked components.
  • Aluminum cylinder heads are dyed to check for cracks.Crankshafts are checked for size and micro-polishedto OEM specifications.
  • If necessary, it is re-ground re-nitrated and micro-polished to OEM specifications.
  • Connecting rods have new bushings installed and both large and small end are remachined to OEM specifications.
  • All heads get new valves and are vacuum tested to ensure the quality of the valve job.
  • All heads are pressure tested.
  • Core plugs are 100% stainless steel to avoid corrosion.
  • NPD replaces 100% internal wear items includingrings, bearings, bushings, gaskets and seals.

Engine: 6.6L Duramax LML, 90 degree V8 diesel
Displacement: 403 cubic inches, 6.6 liters
Head/Block Material: Aluminum cylinder heads, cast iron engine block
Compression Ratio: 16.0 : 1
Firing Order: 1-2-7-8-4-5-6-3
Bore: 4.06″ (103 mm)
Stroke: 3.90″ (99 mm)
Aspiration: Turbocharged & intercooled – Garrett variable vane (VVT), variable geometry turbocharger (VGT) with air-to-air intercooler
Injection: Direct injection, 2000 bar (~30,000 psi) Bosch high pressure common rail w/ CP4 injection pump and piezo injectors
Valvetrain: OHV (overhead valve), 4 valves per cylinder, mechanical roller lifters
Oil Capacity: 10 quarts w/ filter (9.5 liters)
Fuel Compatibility: Ultra low sulfur diesel (ULSD) or max B20 biodiesel blend
Max Shift RPM: 3,000 rpm
Peak Horsepower: 397 hp @ 3,000 rpm
Peak Torque: 765 lb-ft @ 1,600 rpm

Before calling to request price and availability, please gather the following information from the data tag located on the valve cover:

Serial number
Arrangement number
Vehicle/equipment make and model
Sump location (front, rear, center)