None huh? Same thermostat, water pump, fan, fan shroud, coolant, etc?
I would bet that the 2 row Champion uses the same tube dimensions as the Champion three row. Which means the 2 row Champion probably has smaller tubes than the original brass 22" 2 row did, which is why your car now runs hotter. It's just cheaper for them to produce all of their radiators with the same tube size. Which is probably the same reason that Cold Case, the company being repped by Ccas, doesn't sell 3 row radiators. They only use one tube size because it's cheaper to do that. Well, that and they'd have to change their entire sales gimmick if they came out with a 3 row radiator. In your case I would bet that one of those 2 row "big tube" radiators from Ccas would probably work better than your current 2 row Champion. Bigger tubes, more surface area.
Look I'm not a Champion rep, I really don't care. My argument has not been for Champion. They're a cheaply produced radiator and absolutely have the quality control and fit issues that come along with that. The 3 row, 26" Champion radiator that I have has worked flawlessly, but not everyone has had that experience.
My particular beef is the perpetual shlock about 2 row "big tube" radiators and how 3 row radiators are inherently worse. It's a marketing gimmick. Same as the competing manufacturers that say 3 or 4 row radiators are inherently better because they have more rows. Big tubes aren't inherently better. More rows isn't inherently better. In general more surface area is better, but even that depends on the details. The cooling capacity of a radiator depends on a whole bunch of things, and those are only two of many variables. You can have a 3 row that cools better than a 2 row, and a 2 row that cools better than a 3 row, it just depends on the design and construction of those individual radiators. Which is why I keep pressing for more information, so we can actually see which is better based on the DATA.
But since we can't get past the marketing gimmick to real information, we won't know if the 2 row "big tube" radiators that Ccas is trying to sell us actually perform better than the competing 3 rows. All of these radiator companies make sales pitches, most of them count on the buyer not actually having an understanding of thermodynamics.