This 1987 AM General HMMWV was built by Mil-Spec Automotive in Birmingham, Michigan. The vehicle started several years ago as a powertrain test mule for their Launch Edition model Humvee. However last summer CEO Adam Mitchell suggested turning the test mule into a race truck. They started with a fully boxed frame with five crossmembers and altered the full independent suspension geometry for the track. They lowered the Humvee seven inches and installed Wilwood six-piston calipers with vented and slotted rotors behind custom wheels with Pirelli P-Zero tires. Under the hood sits a turbocharged 6.6 L Duramax LBZ V8 that makes 800 horsepower and 1,500 lb-ft of torque to the wheels through a Stage 5 Allison 1000 automatic transmission and ARB air locking differential.
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Source: Mil-Spec Automotive via Autoblog