Now, just as a matter of education. 1. Are all new replacement radiators
> now aluminum? I realize most new car radiators are. 2. Is the regular
> green antifreeze okay. The bottle says it is. I understand there are
> better antifreezes available for aluminum? 3. Is the amount of heat
> exchange as good as copper/brass? I never had an overheat in this car in
> even the hottest weather, AC on in heavy traffic or sitting idling for long
> periods. Will the aluminum radiator still permit that? Physics tells me
> that copper is a better conductor of heat?
No, not all new replacement radiators are aluminum. I got a nice copper one just recently for my '94 Caprice 9c1.
New antifreeze (green or red) is just fine for aluminum. A lot of engines are made of aluminum either whole or in part, so it has to be.
Aluminum actually transfers heat better than copper if I'm not mistaken. Pretty good conductor, and not very corrosion prone. The problem with those radiators are the plastic end tanks, and the how they are attached. It tends to crack and leak, just like you experienced. So it'll be fine, just won't last quite as long as a better one.
Harry