Like a bomb went off under the hood...

In the 60s we ran caps to keep the flies out.
The cooling systems were large,with large upper tanks, more than adequate, and most ran direct-drive fans. And the engine rarely topped 300 hp. If the system is properly sized and in good condition, then hi-pressure is just hard on everything. . My rad is a 1973 model, from a 318Dart with A/C. My heater core is ancient, as are most of the hoses.
Like I said; "since 1999 my engine has never made steam". I guess I should add that while our summers are short, we do get up into the 90s for a week or three, and traffic is traffic, and idling is idling. My cooling system just doesn't care what it has to endure; the stat keeps the temp up, and the 7-blade fan keeps it from creeping any higher.But then, my HO367 is just a little streeter.
My comment was what I run, and I run it cuz it works.