Cylinder Heads
The 6.6L LLY Duramax (2004.5–2006) uses cast aluminum cylinder heads. These heads improve airflow and cooling compared to the earlier LB7. Each head has 32 valves—four per cylinder—and mounts the injectors externally for easier access.
Duramax Cylinder Heads – LLY heads flow exhaust better and have stronger valves. But they can crack or warp under high heat or heavy tuning without upgrades. Performance or remanufactured heads often come with hardened seats, new valve guides, and a resurfaced deck for a better seal.
With the right care or upgrades, LLY heads handle more power, run cleaner, and stay reliable—key for towing and tuned setups.
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LLY Daily Driver Cylinder Head Reman
Price range: $1,000.00 through $1,400.00-
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LLY Workhorse Cylinder Head Reman
Price range: $1,299.00 through $1,699.00-
Select options This product has multiple variants. The options may be chosen on the product page -
LLY Workhorse Plus Cylinder Head Reman
Price range: $1,699.00 through $2,199.00-
Select options This product has multiple variants. The options may be chosen on the product page