1973 360

i didn't see one for dart, but it lists the valiant (so close enough) at under 3K

so that's still 250+ all day without the nitty-gritty of 4spd v automatic, undcoating (+30 lb!!) or powersteering, etc.
69' Dart Swinger 340, four speed was 2800 lbs, advertised a dollar per pound.