If your not going to use the tube for your carb choke heat and it doesn’t leak exhaust gasses it can remain open in my opinion. If I were to permanently close it I would do it with tapped plugs which may or may not change its value to some as the tubes are available and replaceable.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Last stupid question of the day.....not! Does this need to be plugged in some way, shape or form?