My personal experience on the copper/brass vs. aluminum radiators. My 68 Dart GTS, hot 360. I fought a cooling issue for a short length of time. Had a later model A-body radiator, shroud, fan. etc. Everything but the shroud was new, all hoses, water pump, thermostat, radiator, belts, engine was fresh built, fan was new as well. It would consistently run 220 plus and sometimes higher. I actually replaced almost every part on this thing with zero improvement. I tried different fans, water pumps, t-stats, hoses, even another new radiator. Never a single change. Even added a new electric fan added to the front of the radiators. Everything ran the same. Finally, after reading how aluminum dissipates heat faster and more efficient than copper/brass I bought a new one. I even bought one of those cheap units from Ebag. I had to fab up some brackets to mount it. And this was without any kind of fan shroud. I put it in, filled full of collant and I barely ran over 160 again. It could be 90*+ outside and the highest I ever saw it was 170*. I've had the very same experience with my 79 Dodge dually. Had a NEW copper/brass, couldn't keep it cool in the summer with the a/c on. All I did was buy a new aluminum radiator and all cooling issues were gone. This is my personal experience. I will always disagree that a copper/brass is better for cooling.