My Modine aftermarket radiator 3 core was the best damn radiator I ever had.
I could've drove thru Death Valley at 125 degrees outside with A/C on and not even see the temp meter flinch. This is what I experienced with a Copper/Brass. It was way superior to OEM albeit because the fins carried more capacity of coolant than OEM.
Certainly it can be duplicated what Modine did to an OEM numbers radiator I would imagine.
Good article:
I think this guy hit it on the money.
http://www.caparadiator.com/aluminumvscopper.html
Well, not a very good article IMO. His conclusion is: Neither is better! Not very helpful. He even said a two
row aluminum has more cooling surface area than a 4 row copper brass. A 3 row aluminum might
freeze up your engine! (just exaggerating guys!) This seems like a no brainer. An aluminum radiator will out-cool a copper brass virtually all the time.
I had my 26 inch Mopar copper brass rodded out and reconditioned. Still was not cooling well. Put in a 2 row
aluminum Howe radiator, avg temp dropped 20 degrees. Never a problem since, and I use a wimpy electric fan.
And I got rid of the mechanical fan, its weight, and the horsepower it was stealing. Plus, I shed about 25 pounds!
But, to each his own! Go Mopar!
If I had a vapor lock issue, then an aluminum radiator, which might allow me to have an engine that runs 20 degrees cooler,
would seem like a possible solution. Plus, a cooler engine will make more power(ie cooler intake and carb for a colder air charge).