My 383 is a fresh rebuild, pretty much stock cam, with original recored 22 inch radiator in my Challenger. I have a couple of pints of "Water Wetter" in it. The car never, I mean never gets above 160 degrees. It also doesn't run real well between idle and 2000 rpm. My question is, can a car run too cool? The engine setup is stock- exhaust manifolds, heat stove with tube, etc. I'm just wondering if my "flat spot" is related to the engine running cool.