In my Duster I am running a 440 and I have a factory radiator, 26" that has been in there for a long time now. Last year before I took this to Cruisin the Coast I pulled it and had it checked at a local radiator shop and he said it was flowing fine. Didn't see any problems with it. It has been in the car for about 17 years now since the 440 was installed. It cools ok but sometimes in the summer when it gets hot and I have gotten in stop and go traffic or spend a long time at a drive thru the idiot gauge runs up about 1/2 way. some say that is normal. Why don't I put a set of gauges in the car that shows numerals. Because I have restored this car and I show it and I think it doesn't look good. But my idea is to get a new Champion radiator, 26 " and keep the factory fan and then mount a set of dual Spal fans on the front of the radiator. Is that overkill or what. The main reason I am thinking about this is that this year when we take the cars to Cruisin the Coast, I want to run them in the Long Beach parade. Right now I don't believe it would make it without getting hot. I cant imagine that the radiator being 17 years old would be cooling at its maximum capacity. I even thought about just getting the radiator and running it over the summer and see how it does without the Spal fans on the front. But I didn't know if a lot of people ran factory fan blades with electric fans pushing from the front.