Blue', I got the copper/brass "standard core" US Radiator unit, and no issues to date. I've also heard good things from folks who have run the aluminum radiators, but no direct experience.
FWIW, I would not recommend an eFan for a stock setup. These engines tend to run cool if all is good mechanically, and in any event, the stock fan will move more air than an eFan (at some expense in power loss, of course). If you decide to go eFan, recommend SPAL fans, pull style. Panic has it right, pusher fan is a last resort since they block airflow when cruising (when no fan is needed for sufficient airflow). Hope that all makes sense.
Doug
