I had a Champion in my 70 Duster and was able to put on a fan (OE style with lots of pitch compared to aftermarket) and the 2947 short Hayden clutch. It fit, but not by much. I modified a shroud I got from Mancini Racing to fit. Cooled just fine. My current Duster has the 3 core Champion radiator with electric fans I modified to fit. Cools a lot better at low speed than my mech fan did. I am using the aftermarket pulley/bracket kit from CVF Racing because I'm using a magnum engine and the OE 1970 alternator/pulley bracket setup would not fit. The water pump pulley came with flat head bolts, and they were needed to clear the fans. Your mileage may vary, of course!