The pcv valve should plug into the fat fitting 3/8" at the base of the carb the vent would go in the opposite valve cover so it could suck fresh air through the engine to the pcv valve. without the vent the pcv system will NOT work correctly... the vent can be of various type one being a tube that runs to a little filter that is mounted in the breather..another type would be like one of them
chrome filter vents that plugs into the valve cover the one that is opposite side of the pcv valve.... Found a pic of the
vent tube