Nice study Craze, I have a champion rad, with 3 rows with .75 tubes and I have a 160 t-stat and my 400 runs between 180 and 190 on about 95 degree days at around 80-90% humidity driving in different conditions.. IE stop and go, abusing it or just cruising. I cant complain about the temps now and I am happy with it. I was going to get me a 2 row 1 inch tubs, but no one had them available when I got mine over a year ago. Thanks for the indepth study you did!!