Upgrades to my stock 273 67 Dart GT

Nobody's saying they're against a 4 bbl., just that it isn't the priority until he gets his other ducks in a row. And yes, a 2 bbl. can perform, just look at Sportsman short trackers all across the country.
Ignition first. Then exhaust. It's no benefit to get more air in if you can't get it out.
They don't perform they function and are only used because of rules, those engines would pick up a lot of hp if swapped to a 4 bbl. Could he stay stock 2bbl sure but if looking for more power it one of the most basic upgrades there is.