I recently bought edelbrock valve covers for my 91 f150 5.0. I was putting them in today when I noticed that the valve covers I have are slightly different than the stocks; in that the PCV valve hole and oil filler hole on on the wrong ends of the valve covers. My question is can I switch the PCV valve over to the driver side valve cover when in the stock covers it was located on the passenger side rear of the cover? or is this going to mess up the vacuum in the engine? If I can't switch them I guess I will just have to have the PCV at the front of the valve cover and run a longer tube. Advice would be much appreciated.