As mentioned above, avoid epoxy set cores like the plague. The are simply not repairable. The welded cores can be repaired to a certain extent, but not cheaply. Ask a radiator shop about repairing aluminum radiators (not like anybody drives on dirt roads or has ever dropped a tool into the fan). There are also some aluminum radiator myths out there, and some random things to ponder. First, copper is a better conductor of heat than aluminum, but it is a false comparison as most aftermatket radiators typically have far more surface area which more than offsets any difference in material conductivity. Next comes weight, sure your aluminum radiator may have a dry weight which is less than it's OEM counterpart. Another apples to oranges comparison, as most aftermarket radiators are larger and hold more water. At 2 lbs per quart the weight differences as installed probably are probably pretty minor. 4-row cores cool better than 3-rows right? Not always, a lot of times a 4-row will flow less air and actually run hotter in low speed driving. Crossflow radiators cool better right? Balderdash! Heat rises. Most new cars have crossflow radiators because they fit better under todays lower aerodynamic hoodlines. Most new cars also have electric cooling fans, which allow them to use a radiator which is much smaller than would have been installed when our cars were built. A quality electric puller fan is expensive, but well worth considering if cooling is a problem. Electric fans are probably the best setup, but highest initial cost. Cluch fans are next, pretty effective but still not cheap. Fixed blade fans generally aren't too efficient and flex fans are useless for anything other than making noise.
Face it the average A-Body radiator is between 30 and 40 years old, and probably showing its age. A new radiator is far superior to a worn out ineffective one regardless of material. Price out having a new core installed in your original radiator compared to a new aluminum unit. Not hard to see why aluminum replacements are so popular. Copper is way more expensive, (remember that pennies have been made of aluminum for over 20 years now.) Builders commonly have the wiring stolen out of their jobsites, yet few theives are currently absconding with storm windows. The same radiator that Summit sells would be outrageously expensive if made out of copper/brass. I'm not really trying to bash aluminum radiators, but sometimes we need to look past the pretty pictures and slick marketing in the catologs and analyze the big picture.
