What brakes fit??
Does it have 4 piston calipers, if so that would be the kelsey hayes I believe which was available for 72 and before. If they are of the single piston type most likely they are from 73-up dodge, also the most common. Just ask for a set for a 73 or so dart, and there you go. Just bring in the old pads to compare. If they don't match up after that I'd take a few pics of everything and post.