We've used aluminum in the last 4 cars and I think I am going to stick with aluminum from now on. I think they do dissipate heat a little better than copper or brass ones, in fact I am having trouble getting my T up to the correct temperature and almost never run the electric fan.

I also have one in my Jeep that has a 5.0 Ford in it. Because of space limitations (height) I had to go with a smaller one that I wanted, but it still does fine, even here in Florida. My '27 has a custom made one by the brassworks in California, and it never quite kept the temp down like the aluminum ones have done.

A big part of it is a full shroud and a good electric or mechanical fan, regardless of the type of radiator being used.

Don