I had over heating problems on my aluminum headed small block Dart a few years ago. It had a new replacement radiator with a Flex o Lite Black Magic electric fan on it, standard wp and 180* thermostat. I went to a new aluminum radiator with a new Flex o Lite thin fan, 2700 cfm. It still ran hot so I changed to a Flow Kooler wp and a high flow 160* thermostat, still hot. The fix was a MP (5 blade) viscous fan package and a factory shroud that I modified to fit the aluminum radiator. My car doesn't have air so it's not apples to apples, just my experience .

Edit** This car has 4.30 gears and a 9.5" 4400 converter.