I remember the first retro smog control requirement in SoCal was to plug the breather tube, Install a PCV valve in the valve cover with an attached hose to the air cleaner. I think I remember that right. Anyway plugging the breather tube ended the majority of the oil drips in driveways and parking spaces.
Judge Tom Lee’s dad, R. J. (****) Lee running the wireline checking the bottom hole pressure on a well.