Nothing wrong with stock radiators. No need to buy aluminum. If you want to keep your Harrison tanks, send the unit to Glen-Ray. He's done work for me and it top notch. http://www.restorationradiators.com/
If you want, melt off your tanks and just ship them. Don't throw out your old tanks. Give or sell them to people who have radiators properly re-cored. Be very careful of radiator shops who claim to do quality restoration work. Many are hacks. Good shops know that manual and auto tranny filler necks are clocked differently, what drain petcock is correct, and how much solder should be exposed. Many hammer on the solder and the result looks awful.
Radiators have rows. Many refer to radiators as 2,3 and 4 core, which is wrong. The core is the unit between the tanks.