Best coolant for our 60-70's Mopars?

I've been running Evans in my Barracuda (408) and my Duster (440). From personal experience I can say that the temperature does rub warmer. For me it's about 10'. I have been able to open the cap on the radiator no matter what my gauge shows without worrying about getting sprayed with boiling water. There is never any coolant transferred to my expansion tanks.
Just curious as to what pressure cap you are running...and is there any air gap in the top tank of the radiator?