This photo shows both the old- (pre-'05) and new-style ('05-and-later) high-pressure oil stands for the 6.0L lubrication system. Notice that the new version (top) includes an integrated check valve (arrow). The primary function of these metallic tubes is to deliver engine oil discharged from the high-pressure oil pump to each of the two high-pressure oil rails on top of each cylinder head. The improved versions retain engine oil at the top of the engine to help the system reach operational pressure as soon as you turn the key. This upgrade reduces the total number of rotations it takes to start the engine-another commonly reported problem with the 6.0L. These pipes are a factory retrofit and are automatically included with all new 6.0L head gasket kits from Ford.