Before you do a whole lot of diagnostics, please disable the PCV valve and vent to the atmosphere. It is possible that there is something missing in your valve cover to keep the majority of the oil from the PCV valve. I once had a F--D truck that took an unbelievable amount of oil. I replaced the PCV valve and it didn't help. I finally just plugged the intake where the hose went from the PCV valve and vented the fumes to the atmosphere. The oil consumption went to almost nothing. I still believe something was missing in the valve cover and it was sucking way too much oil through the PCV valve. Anyway, it is fixed now with no PCV valve.
