Doing brakes on a 72 Dart. Any upgrades or pad advice?

Check 'em and adjust them. If they haven't been bled in a year or two, bleed them. That's the only item that needs service just due to time. The brake fluid absorbs moisture and eventually that degrades it perfromance and corrosion resisting inhibitors. In a moist humid climate its worse. In my experience, disk brakes are more susceptible to rust issues and I bleed my car's brakes once a year. Anyone racing ought to due that just as a precaution.

If the lining is worn down to or near the limits, then replace the shoes or pads. With shoes, its better to buy a new spring kit at the same time. Last but not least, make sure the new linings have friction properties as good as the old. Too much junk sold these days. The edge code is a rough guide to that.