Miss Maylene

So went out to dads today, where I store my cars at, I was looking at getting new tires for the dart because the old one won't hold air and when looking at the fronts I noticed they have 73+ calibers on them and rear mounted. I was under the impression that I had the Kelsey Hayes which mount in the front? My car is a late 72 made in February I believe, could they have used the later brakes? The fender tag says factory disc brake. So just a little confused. I will spend some time Sunday checking it.