Couldn't resist a reply,,haha. Being a pretty hardcore circle tracker, needless to say we are pretty demanding of our cooling systems.
We have used aluminum radiators before, solely for the purpose of reducing static weight on the front of the racecar, that, and eye appeal are the only reason to use aluminum. I am sure some have put them in and seen an improvement on the street, but I promise that is only because what they had before was not adequate to begin with.
The hands down best heat tranfer comes from a copper brass radiator, with a HD high efficiency core and a perfect, not workable, but perfect, fitting fan shroud. As far as a 3 row core vs. 4 row core, that depends on your usage and if you have ac. I work very closely with a radiator builder in our racing ventures and have really picked up a lot of insight on cooling systems over the years, and always glad to help out. If you need more info feel free to drop me a note, as with work and family, I don't get to check posts too often!!
Jeff, speedy_87ss@yahoo.com