1972 fuel tank venting
If you're tank is non vented, then I suspect you'll have to track down a vented filler neck, and vent it to the atmosphere (not in the trunk). The '72 can be converted to a vented neck by adding a nipple high in the neck, and attaching the appropriate plumbing. Like this.......... I am using a 1970 Duster filler neck on my 1971 Demon as I acquired a non vented tank as well. Good luck.
If you're tank is non vented, then I suspect you'll have to track down a vented filler neck, and vent it to the atmosphere (not in the trunk). The '72 can be converted to a vented neck by adding a nipple high in the neck, and attaching the appropriate plumbing. Like this.......... I am using a 1970 Duster filler neck on my 1971 Demon as I acquired a non vented tank as well. Good luck.