Duramax 6.6L LBZ V8
Horsepower
360 hp
Torque
650 lb-ft
Years produced
2006–2007
Aspiration
Turbocharged
- Configuration
- V8, 6.6 L
- Aspiration
- Turbocharged
- Builder
- DMAX Ltd.
- Designers
- Joint venture of GM and Isuzu (DMAX); engine blocks supplied by Fritz Winter
- Years
- 2006–2007
Offered in: Chevrolet Chevrolet Silverado 2500HD, Chevrolet Chevrolet Silverado 3500, GMC GMC Sierra 2500HD, GMC GMC Sierra 3500
The LBZ, rated at 360 hp and 650 lb-ft, arrived in 2006 with revised internals and a six-speed Allison automatic. It was used in the Silverado and Sierra HD trucks through the 2007 Classic models. It predates the diesel particulate filter that came with the LMM, and is one of the engines enthusiasts most often seek out.
What made it successful
It combined a large power increase with reinforced durability and sat before the particulate filter era, which is a large part of its reputation.
Market position
Its 360 hp and 650 lb-ft placed it at the top of GM's diesel line. Sourced comparisons with Ford and Ram are not yet included.
Rebuild Potential
Tier AEditorial opinion.
The LBZ carries the strongest reputation in the family, has full parts and aftermarket support, and avoids the particulate filter. It corrected the LLY's main cooling weakness with a larger radiator and improved airflow. It scores at the top on support; the drawback is that clean trucks command high prices.
Best year ranges
- 2006-2007: The only years for this engine; it has the larger cooling system and fan, and predates the particulate filter.
Known weak points
Some trucks still run hot under heavy towing when airflow or fan engagement is compromised.
Common fix: Diagnose airflow, fan clutch, and coolant condition first, then refresh the cooling components.
Common upgrade categories
- Cooling and fan clutch service parts
- Injector and fuel system refresh
- Head stud and gasket upgrades
- Transmission cooling and Allison service parts
- Bolt-on intake and exhaust within local legal limits
Keep the emissions equipment the truck was built with. Removing or defeating it on a vehicle originally equipped with it is illegal under federal law. Rules vary by state (for example California/CARB), so check local law and model-year requirements before modifying.
Sources
- Duramax V8 engine (Wikipedia) (accessed 2026-09-18)
- Chevrolet Silverado, first generation (Wikipedia) (accessed 2026-09-18)