Way back in 2001, the LB7 Duramax engine made its debut in Chevrolet and GMC HD trucks. The LB7 Duramax was considered revolutionary when released and utilized a turbocharger, intercooler, and direct injection. A huge highlight of the engine was the common rail technology and the use of aluminum cylinder heads. Until then, this lightweight alloy was typically not found on top of a diesel engine.
However, like most first iterations, the LB7 Duramax was far from perfect. Take for instance the fuel injectors. The LB7 came equipped with injector nozzle “cups”. These injector cups tightly seat into the cylinder head and are held in by the injector via the injector hold down. A common problem associated with these sleeves is they can lift slightly out of the head. This can lead to compression loss, which can in turn pressurize the cooling system. This is commonly mistaken for blown head gaskets and usually ends up in costly and unnecessary repairs.
But thanks to Fleece Performance, there is an upgrade that can solve all your LB7 cylinder head woes. Check out the Freedom Series cylinder heads for the LB7 6.6-liter Duramax. This all-new cylinder head features a cupless injector bore. By installing the Freedom series heads, you can actually save time and money with no more injector cups to install, leak, or worry about.
Each cylinder head is assembled from a new casting in Fleece’s state-of-the-art Freedom Racing Engine shop and is guaranteed to meet or exceed factory specifications. All heads are CNC-machined and feature a multi-angle valve job, are meticulously inspected, pressure and leak tested, and are equipped with new valve guides, springs, and valve seals. These are perfect for your daily driver or towing application.
When upgrading and installing these heads, Fleece recommends using the following: GM 12637788 head gasket (Grade C, right) and GM 12637785 head gasket (Grade C, left)