2005 GMC Sierra Duramax - The Next Level. ... The stock Duramax long-block is fine for 500 rear-wheel horsepower all day long, but problems may occur as power levels approach 700 rwhp.

Even at the 478 rear-wheel-horsepower level, Blount's 2WD Duramax was a blast to drive, ... However, 168 hp and 320 lb-ft of torque over stock at the wheels is still impressive in our book.

The DEF level sensor of the affected Chevy Silverado, ... GM ought to include the DEF sensor on the L5P 6.6L Duramax on the 2017-2019 truck too.