Hummer H1 & H2 Duramax Diesel Conversions – OLD PAGE

Available for both the H1 and H2 Hummer

The Duramax Power Train conversion begins by removing the stock engine, transmission and transfer case and replacing with the Duramax Engine, Allison Heavy Duty 6-speed Transmission and selectable 2wd/4wd transfer case. Each conversion consists of a engine, transmission, and transfer case. Additional, custom and one off upgrades, are available such as paint, suspension, interior work, exterior styling options and various theme builds. The Duramax conversion will now enables you to operate a selectable 2wd/4wd system which increases fuel economy up to 26mpg! During the conversion, many new items are installed such as a new intercooler, fuel cooler, Duramax Wiring Harness, Modified ECM and several hundred other items that go into the massive conversion process.

Duramax Engine:

Predator H1 & H2 Duramax Engines
The Duramax Diesel 6600 V8 is the most powerful engine in its class. The stock base power rating is 300 horsepower at 3100 rpm and 520 lb.-ft. of torque at 1800 rpm however this engine is capable of being built up to 800hp and 1400 lb.-ft of torque by our team of diesel engineers. The block is case hardened and incorporates a one-piece aluminum crankcase and one-piece aluminum bell housing which helps reduce noise, vibration and harshness.

Allison Transmission:

Cummins Conversion Allison Transmission - Predator Inc.
Advanced electronic controls enable constant communication and feedback between engine and transmission, resulting in more precise, more efficient, faster, smoother, fully automatic shifts. With technology to match its legendary durability, the Allison Automatic is the perfect match for the H1 and H2 Hummer and the 6.6-liter Duramax diesel engine. A few key components to the Allison Transmission besides its legendary strength are its Grade Braking allowing for better downhill control, Adaptive Shift Control allowing for an adaptive shifting pattern depending upon driving conditions and driver inputs, and finally a Fuel Economy System which is electronically optimized to shift at just the right point in the power curve, smooth­ness and swiftness are not the only benefits. Less wasted rpm’s means less wasted fuel, which means lower costs along with extended range.

Performance upgrades:

We offer many performance upgrades to suite your needs including several levels of performance ranging from 450hp to 800hp and 1400ft/lbs of torque. Each vehicle is uniquely built for each customers specific needs.

Performance options:

  • 5 position selectable digital power enhancement which also clocks your 0-60 and ¼ mile times
  • Larger injectors
  • 60psi Turbo
  • 4” Down Pipe
  • Performance Fuel Management Computer
  • Performance Transmission Computer
  • Billet Triple Lock Torque Converter
  • Performance Transmission Upgrade (able to hold 800hp and 1400 ft. lbs of torque)
  • Water Injection
  • Propane Injection
  • Nitrous Injection
  • Heavy Duty Head Stud Kit
  • Exhaust Brake
  • And many more…

For more information please call one of our Duramax specialists at 877-733-2867

Compare your engine to our Predator Duramax Conversion

Select your engine below to compare the difference.


6.2L (1982-1993)

6.5L (1992-Present)

6.5L Turbo Diesel (1992-Present)

6.6 Duramx Alpha (2004-2005)

5.7L Gas Hummer (1995-1996)
Engine (Manufactured Years)6.2L (1982-1993)6.5L (1992-Present)6.5L Turbo Diesel (1992-Present)6.6 Duramx Alpha (2004-2005)5.7L Gas Hummer (1995-1996)6.6L Duramax Predator Conversion (2006 – Present)
Hummer Models1992-1993 Hummer H11994-1995 Hummer H11996-2004 Hummer H12006 Hummer H1 AlphaAll Hummers and HMMWV’s
ConfigurationV-8V-8V-8V-8V-8V8
Block/Head MaterialCast Iron Block, Cast Iron HeadsCast Iron Block, Cast Iron HeadsCast Iron Block, Cast Iron Heads
Displacement379 cublic inches, 6.2L395 Cubis Inches, 6.5L395 Cubis Inches, 6.5L403 cubic inches, 6.6 liters403 cubic inches, 6.6 liters
Compression21.5:118:1?????17.5:116.8:1
Bore3.98 inches4.06 inches4.06 inches4.06 inches
Stroke3.80 inches3.82 inches3.82 inches3.90 inches
InjectionIDI (indirect injection), mechanical rotary pump26,000 PSI Bosch High Pressure common rail w/ cp3 injection pump
Aspirationnon-turbo, naturally aspiratednon-turbo, naturally aspiratedTurbocharged Naturally Asprirated versions Availableintercooler& variable Geometry Turbocharger
Max Engine Speed3,600 rpm3,400 RPM3,400 RPM3,450 rpm
HorsepowerIntroductory: 150 HP@ 3,600 RPMIntroductory: 170 hp @ 3,400 RpmIntroductory: 195 hp @ 3,400 Rpm300 HP @ 3,000 rpm465 HP @ 3,100 rpm
TorqueIntroductory: 250 lb-ft. @ 2,000 RPMintroductory: 290 hp @ 1,700 RPMintroductory: 440 lb-ft.@ 1,800 rpm520 lb-ft @ 1,500 rpm960 Ib-ft @ 1,800 RPM
Transmission3-Speed 3L804-Speed 4L80E4-Speed 4L80E5-Speed Allison HD 10006-Speed Allison HD 1000
Estimated Fuel Economy10 mpg10 mpg12 mpg9 mpg18 mpg
0-60 mph23.1 Seconds26.3 Seconds16.4 Seconds13.5 Seconds16.2 Seconds
1/4 mile22.4 Seconds23.3 Seconds20.4 Seconds20.5 Seconds
RPM at 65mph
Top Speed68 mph83 mph83+ mph with Turbo
Estimated Life Span between Overhauls200,000 miles200,000 miles100,000 miles500,000 miles150,000 miles500,000 miles