Why did you select a 3 row over a 2 row radiator from Champion?
I have been looking at their radiators and haven't done anything because I am unsure for my 340.
Champion claims a 2 row will cool to 450 hp and a 3 row to 700 hp.
So I have wondered, is more really better? Also saving $40 (or so) with the 2 row sounds better to me.
I will be interested to hear about your results if/when you change your thermostat...so keep us posted on your results.
Paul