I've had 3 champions. In the bb duster I have a 26" 3 core with the stock opening. I have a home made shroud and a clutch fan. It works great. Stays under 180. Been In there 8 years.
In my magnum powered wrangler i also have a 3 core champion. You have to see how small that rad is. I want to say 18" wide. I have a pt cruiser electric fan and that also works good.
I did have one that a dozen or so tubes started leaking, I tried to warranty it since it was only 1-1/2 to 2 years old, but since I had a tube that I damaged and closed off with epoxy, I voided the warranty. I'm still curious what caused that. I replaced it with a blem unit i got on eBay that had the wrong size outlets. Cut them off the old one and welded them on the new one.
I have to replace the cheap cross flow in my dart and I think I'll try the ecp.