DW: What makes DURAMAX so fantastic?

It's impossible to tell where GM's heavy duty Diesel pickups trucks will be today if the Duramax were never born. The car giant was desperate in the late 90s to get their hands on the 3 percent slice kept in the domestic truck pie. But after the 5.7L fiasco in the late 70s and early '80s, and experience and understanding of the platforms of 6.2L and 6.5L, GM realized that its next oil-burning venture would need homerun. Turning to the Japanese vehicle and engine manufacturer Isuzu, as a joint venture of DMAX Limited, it was a longtime stakeholder. Isuzu handles the base configuration of the Duramax engine while GM handles the integration into its vehicles.          

As proof that GM and Isuzu got it near perfect right out of the gate, the basic design of the 6.6L has remained the same for 20 years now. It still sports a deep-skirt, cast-iron block with induction-hardened cylinders, four-valve aluminum heads with six head bolts per cylinder, and clean-burning, quiet operating, common-rail combustion. For a look at what makes the "dura" (for durable) in the name of Duramax, we will discuss the hard-parts of the OEM that make it possible. Then we will explore the time-tested aftermarket components that make GM's 6.6L V-8 almost indestructible, building upon an already-stout base.

Source:-Diesel World