My Big Block does not like traffic on hot days. Runs cool at city or highway speeds. 26 inch 3 row alum rad..6 blade steel fan..shroud(blades half in/half out) stock waterpump 180 degree milodin thermostat. Now it appears to me that it is not getting enough air flow through the rad at idle or the waterpump could be upgraded to a high flow. It's a 67 dodge and there is not enough room for stock fan and electric fan.

so is the answer an electric fan system that can push air at the equivolent of 30 to 40 mph , what would be the cfm, or try the HV waterpump? Thanks in advance to all.