Fuel sender hook up

Do a search and find some of these, I'm sure it is meant for a return line and not a vent. If your tank originally had the trunk can vapor separator, there should be more than one (4) vents from the tank to that can, and then "the" vent was the 1/4" line which ran all the way up front to the carbon can system. You cannot plug the vent. There are a few ways but it depends on what you "have" and what you want to do

If this is a replacement tank it "may" have just one vent line.

Still another way is to duplicate the 69/ earlier vent which was a nipple up high in the trunk for the vent.

First is you need to figure out what your tank has, that will dictate your options.

Go to Mymopar and download the 70/ 71/ 72/ 73 manuals, and you will see the differences in the system. Part of it is detailed in "fuel" and part of it is in the back of the book in "emissions"