LA block 360 won't stay cool

I have a 360 with 400hp in my 70 Duster with AC and auto trans. I have a 22" 2 row aluminum radiator with a flex fan and 2x7" electric fans in front of the AC heat exchanger and a 160 thermostat. It has an aluminum water pump. In cool weather it stays cool but when it hits 90 it won't stay cool in traffic with the AC on and hits 195 to 200 even with the AC off. Any ideas? I have a 1968 Sport Fury with a stroked big block with 600hp and the same radiator and fan set up and it never gets over 170.