Can you change vent and filler tube

vent for a 1970 Dart (assuming it's not a CA emissions car) is off a nipple on the filler tube and runs through a metal line through the trunk floor/filler tube rubber gasket into the frame (and just ends!). No vented cap needed, but the vent line is. This is one of the "mount from inside the trunk style" mentioned in the last post. It's that nipple for the vent that keeps you from putting the filler tube in from the outside.