BY MIKE MCGLOTHLIN | PHOTOS BY MIKE MCGLOTHLIN AND COURTESY OF THE MANUFACTURERS
For nearly two decades, GM has stuck with the same basic engine platform that revolutionized the diesel truck segment back in 2001. Though it’s undergone many alterations and been given six different RPO codes over the years, in a lot of ways the same basic cast-iron block, aluminum headed, 6.6L common-rail V-8 remains. Not even the production run of the 5.9L Cummins lasted as long as the Duramax engine’s has (in pickup applications, anyway). For nearly 20 years, GM fans have been expanding the performance potential of the Duramax—and at this point the aftermarket practically has it down to a science.