Put new rotors on 73 Swinger and pads are rubbing!?

If it took an inn ordinate amount of pressure to retract the caliper pistons, then you might need to rebuild the calipers. I just had this exact issue with my Jeep. A set of rebuilt calipers solved the issue. But in my case it was glaringly obvious that there was a problem, as the pistons did not go in easily. If the rotors turn out to be in spec, look to the calipers, I'd say.