Almost every post that starts with a "I have an overheating problem" , also states Aluminum radiator, electric fans, and fancy shroud. You almost never see one where there is a stock 2 or 3 core copper /brass radiator, factory or no shroud, and stock mechanical fan.
My 340, runs all year in Tampa, at 180, may creep a Lil at a long light w/ a stock set up. Except, I ditched the flex fan, and grabbed a clutch unit and fan. Still, never ran hot before that.