Oil System Stand Pipe for the 2003 and early 2004 (Round Style EGR Cooler vintage) Ford 6.0L Diesel. There is one stand pipe per cylinder head. These stand pipes conduct high pressure oil from the branch tubes to oil rail. Its a great idea to change and update these parts if you are going to have the valve covers off. These parts have o-rings (two) on them that can start to leak. If you are changing your injectors, head gaskets or just even have the valve covers off, these are good parts to service/change for maintenance purposes.