Flip fuel cap on Duster need to be vented?

I did notice that difference in the filler neck on my 1972 Duster versus my Dad’s 1966 Dart. Had a thought on a work around being that I could weld a pipe thread bung into the filler neck on the 1972 Duster that is flush on the outside of the tube and then thread a hose barb fitting in with thread sealant after it’s back in the car.