power steering box

What is a good power steering box for a 73-76 Dart Sport or Duster. Where did you get it. Last year I had to buy one for the Dart Sport and I have adjusted it twice and it is loose. It was from Oreillys and they don't have them any more. I have looked at A1 Cardone through Summit and the reviews aren't that great. The ones from Autozone is that great also. Thanks