What I DO know is last year I pulled the original out and put in a mongo aluminum with large electric fan, and now I never have gone over 200 degrees since then, even in 100 degree summer driving.
I still look at the darn temp gauge every 10 seconds though, thanks to the old radiator habit. I don't think you can ever break from that habit after worrying about the temp for all those years.
'68 428 HO M3 Monster, 4-on-the-floor! Need I say more?