I know a guy with a '65 GTO clone with a worn out 455 and original two row radiator. He swapped some higher compression heads on and made some other changes for more power. The car runs well, but over heats after a short time of driving, mainly from the 3.55 gears and more rpm they created. For cooling, the car had the stock old radiator, no shroud, and worn out fan clutch. I suggested a new clutch for the fan, new shroud for the fan, and a two core, aluminum radiator, which would have been plenty of cooling. He instead bought a Champion radiator, aluminum two core which is what the car needed, but then installed a dual electric fan / shroud combo wired to the ignition circuit. The car overheats even quicker now, and blows fuses every other time the fans are turned on manually. The shroud / fan combo sets about 3/4" to 1" off the core with two 12" electric fans, no other openings. At higher speeds, the only air through the core has to go through the 12" partially blocked holes. The fans are 800 cfm each, so even at idle, the air flow is lacking. This type of engine should have at a minimum, 2000 cfm air at idle through the radiator. I have read, a good working clutch fan can pull 9000 cfm when needed.
It's a long story I know, but my point is, be sure you understand what you are buying. Champion radiators are good, they fit well and do what is required of them, its the electric fans that cause all the problems.
This still holds true, if the fan won't hold a shop rag to the grill when the engines is running, it won't cool correctly!
