Freedom Series Duramax Cylinder Head with Cupless Injector Bore for 2001-2004 LB7 (Driver Side) Fleece PerformanceFreedom Series cylinder heads for the LB7 6. 6L Duramax now with a cupless injector bore 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 our state of the art Freedom Racing Engine shop and is guaranteed to meet or exceed factory specifications. All heads are meticulously inspected, pressure and leak tested, and are equipped with new valve guides, springs, and valve