oil cap

["MonteMorris" <mmorris@nemr.net>]

Our 67B has a 1973, 18V motor in it with the only pollution control being
the PCV valve. The valve cover has a vented port at the rear at right angles
to the cover (I currently have it plugged).  If I remove the PCV valve, plug
the remaining hole in the intake manifold, and put a small air filter on the
tappet cover pipe that once led to the PCV valve, do I now need a vented oil
filler cap?
I'm taking several lister's advice here, trying to get rid of an oil
consumption problem.
Thanks,
Monte