and introduced a replacement engine mid-way into the Duramax's third year. GM debuted a revised engine, the LLY, mid-way through 2004 for the Chevy Silverado and GMC Sierra 2500HD/3500HD — thus ...

The mid-2000s was a period of rapid iteration for GM's Duramax engine. The LLY only lasted a couple of years before GM debuted an updated version of the 6.6-liter diesel with a new code name ...