[DeTomaso] Extra Connection On Gas Tank

[MyCars]

Hello,
My early push button car has an extra vent on it. What should I do with it?
Since I took the picture and thought about it a little more... I 
remembered that the fuel sender is new and it has a new gas pickup (the 
old original sender did not).

Should I just plug the old connection?

http://mycars.home.comcast.net/~mycars/Pantera/TopOfGasTank.jpg

Thanks
Roydon