1967 Plymouth Barracuda - Fuel tank not vented properly??????

Bodyperson said
The factory didn't give us a check valve. Mine was plugged with mud from Daubers.

I don't remember ever seeing anything on mine from the factory. I'm assuming the later years the vent was part of the evap charcoal system. But mine had never worked since I owned the car it's always puked gas out of the filler