1970 Duster gas tank venting

Alaskan_TA said
You can just cap the 4 tank nipples since your filler tube has the correct vent for your original application.

I would only do this as a very last resort. I've seen those vent tubes crack or even break-out from the side of the tank on 2 different vehicles. This causes gas leak/seepage/fumes. Royal pain to deal with.