rebuilding front disc calipers
The 74 Dart Sport I did with my son has what are called sliding calipers. The only parts involved in "rebuilding" them was a new seal and dust boot, just like you described. I'm sure you're not referring to the anti-rattle springs, etc.
The part that is throwing me for a loop is that, as far as I know, 74 Valiants did not have rear disk brakes. Yours must have some that are aftermarket or owner-swapped.
Photos, maybe???
Jerry