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. (Dick) Lee running the wireline checking the bottom hole pressure on a well.