Vapor port on fuel tank

No, because it IS the vent. The only way I would know is either
A leave it as a vent and create another port for return, either mod the sender or braze or somehow put a port into the tank. They make mechanical / gasketed fittings that you may be able to install through the sender hole

B...Modify the fuel filler tube AKA put a vent fitting in the tube and duplicate the 69/ earlier type vent. Those ARE simple and work well