Front calipers

[chevyhed53]

I'm discovering painfully late that almost no one has front brake calipers that will work with a '70 C10 spindle and 12" rotor. I'm redoing the front end and bought new '70 spindles, then realized the calipers I had sitting in a box for years would not fit that spindle. I figured a quick trip to OReillys or Autozone would do it, but no one has calipers older than '71. Am I going to have to do '71-'72 ball joints to accommodate a '71-'72 spindle or is there another solution?
Thanks!