There are actually a lot of subtle differences.
Strut rods have a different thread. - My 73 has coarse and a set of 72's have fine thread
Sway bar on a 73 passes through the k frame and 70-72 it mounts to the front out side the k frame.
Center link, idler arm and pitman arm have a different angle. - kind of hard to describe.
....I'll look for some pics...I've seen them on here but it's been a WHILE.