James
I PMed ya back.. FWIW I've always used a four row core with good results, I've read opinion about the need for it.. I live in an area where 100+ is pretty common, my cars never overheat... FWIW when first starting a new engine with a nice new/recored/rodded out radiator I suggest using a filter in the upper radiator hose to catch the debris that can clog your new radiator... I typically run the filter for a few weeks then replace the upper hose.. During the time your running the filter it's not uncommon to have the remove the filter three-five times to clean debris out of it...

Radiator filter
Gano Filter Company
1205 Sandalwood Lane
Los Altos, California 94024
(650) 968-7017