Copper/brass radiators are far-better conductors of heat than aluminum. Unfortunately, with the price of copper being nothing short of exorbitant they're getting hard to find. Many replacement radiators for older cars are now aluminum cores with plastic tanks. This was the case with the radiator for the LeBaron (which will now likely end up in the Imperial; I can't find another inexpensive one). The application is a '78 D/W250 with a 360 and max cooling. It's a 28"-wide 3-row core.
When I ordered it, my cost on it was around $160. I just left it in stock, on the shelf, until such time as I felt I needed to purchase it. That was, until it came up on an inventory count and I saw my cost on it had skyrocketed to $290!! So, I shipped it back, and called a local radiator supplier, who found me an all-aluminum unit for around $200 with shipping. I decided to do a little digging on my own, and I found exactly one radiator in our system of a different brand with cost of around $155. I ordered and bought it immediately. I think I may have even paid for it prior to its arrival. That radiator is now discontinued; it was the last one we were ever going to receive (I tried). I have a corroded 2-row version of same I may have recored with a 3-row core, which will cost more than the one I bought new.
Should the time come where I need to buy a Griffin, BeCool, etc. aftermarket radiator it will receive a nice coat of black paint. I think they look hideous, as do copper/brass radiators with polished tanks. Why steal the thunder from the real centerpiece of the open hood--the engine?
