Sorry to hear about you having rats!. Anyways, the correct oil filler cap in OPGI catalog is part number GTE0017. It is a "twist on", NOT "screw on". You will have to plug the hole in the valve cover where the hose for the emissions went or, as I would do, replace with an original valve cover. It will look nicer. I am not that familiar w/Cali emission cars, browse around the internet, I remember seeing the diagram of emission/non-emission cars. Later, I will look for my original '66 manual and find it.