First problem, you live in a warm weather climate and it's very humid there. If it was recommended 2500 CFM fan should always go larger, never on the border, because in FL it will work hard and with a Pontiac engine even harder. Look into the stock filler pans for the top of the radiator and the bottom. Sorry to burst your bubble but the robbing of horsepower of a stock fan over an electric, if you notice it with a 400ci then the engine is junk. I would never trust an electric over a belt driven fan. That electric motor quits it's Goodbye engine, at least with a belt driven I have to lose both belts. Call me old fashioned. I'm an electrician by trade and I know electric motors overheat and seize without warning.
