'72 Dart w/360 cooling issues

Is there a gap around the sides, or over the top, of the radiator to allow air to bypass going through the core? If so, sealing up those areas can help. If air can find a way to go around the radiator it will, you have to force it through the core. This is especially true with thick aluminum radiators. Take a look at the front of my car. I don't have near the frontal area you guys do but due to proper ducting it runs 180-185 degrees going down the highway in 100 degree heat. You should be able to accomplish the same thing quite easily with all the frontal area you guys are so so lucky to have :).