Differences between 70/71 and 72 Darts
In addition to the differences listed above, wiper motors are different, dashboards and instrument clusters are different, seat belts are different, some wiring is different, bumpers are different to accommodate the new-for-'72 hook-and-slot style bumper jack, the evaporative emission control system is quite different (see
here for detail), and of course interior patterns, trim, emblems, and available colors are different.