I've narrowed down a persistent oil leak to most likely be coming from the High Pressure Oil Rail Plug on the drivers side.

Does anyone have the Ford Part # for the new style plug?

Thanks in advance,

rhodester

 

Oil Rail End Plugs - UVC Cylinder Heads

 

Most guys over look the HPO Rail Plug when replacing other orings and here is a case that they do and will leak due to the old design of oring. The new design is much better. But when you replace the oring it is very important that you get the threads in the head clean and dry and use the correct Loctite 277 and alittle grease on the edge of the oring. And I would also replace the banjo bolt oring also since you will be right there.
Here is a photo of the old design verse new design.