I will be doing a drum to front disc conversion on my 69 soon. I plan to mill off .590 from my drum spindles to make them work for disc. After I do that, I will need rotors. (I have caliper brackets, hose brakets, etc.)Is there any difference between 69-72 front disc rotors and those that fit the 73-78 GM A bodies. I see some at a boneyard nearby and they sell for 7 bucks each, and if they have enough meat to cut them true, I'd save some bucks. Are 68-72 disc rotors unique to the spindles for those years?

anybody know the answer to my above question?

I do not know the real answer to this, but I will suggest a way to find it. Go the web site for Checker or Autozone and look up the part numbers for those rotors. If they are the same, you are in luck.