The LLY was the second-generation 6.6L Duramax, used in 2004.5-2005 (into early 2006) Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks. It was the first Duramax with a variable-geometry turbo and is known for running warm under heavy load. We carry OEM-brand LLY parts - fuel injectors, CP3 injection pumps, turbochargers, and related fuel-system and engine components - many with no core charge and fast US shipping. Because Duramax parts vary by generation, verify the part against your LLY by OEM cross-reference before ordering.