Brass or aluminium radiator?

My 91 has alumimum, it would be copper not brass but fins are probably aluminum

Never seen copper save for Ford Model-T! Copper is orange and brass is gold color. My 03 Camry is plastic (argh) top and bottom and Aluminum fins/cooling area.

My 1994 has an aluminum radiator. Sounds like yours was replaced by an after market substitute. The original had plastic upper and lower tanks and all aluminum construction. I have never owned a car that stayed cool as well as this one regardless of conditions. I suspect the radiator is oversized for the requirements to minimize the electric fans cycling on. Saw a neighbor's four cylinder Honda once and the radiator was much, much smaller. Aluminum will radiate heat very quickly, and is also lighter in weight.