1. Fans blowing in right direction.
2. Shroud something to look at, no room between fan and water pump pully on A body with hemi. May have to modify fan to make 3/4" gap. Current gap between radiator core and shroud in 3/8". rick Did moving shroud fix your issue?
3. Ran straight anti freeze in all cars, 600HP 500 inch wedge never went over 185 degrees in traffic. May have to try if shroud doesn't work. Yes pumps do differ. Ran the Mopar aluminum on all my cars without problems.

Thanks to all with ideas. Any others?