Replacement radiator???

I have a 1939 chevy 1/2 ton pickup and wondering is it better to use a copper radiator or an aluminum radiator? Running a mild 350 with 350 trans in it. In the build state currently. Thanks for the imput

 

If its mild copper is fine. Im running 450hp 383 stroker with 3 core copper radiator. I live in florida and no over heating problems. Dosnt even get over 190 degrees. Im also running aluminum heads though. Cools alittle better.