Well thats what I heard was the case wit da old flatties I think, they would take out the thermostat and it would run through too fast and not absorb any heat. But as for goin through the rad too fast..I don't think so. I have a really good way for you to find out if it is cooling efficiently enough. Get a heat gun sensor, you know...the type that uses a laser to give you a readout? Test the coolant temp at the top of the rad and at the bottom, if there is hardly any diff then you got a prob with the rad or weak pump. The most drop I think you should get is about 40 degrees C which is whatever it is in Fahrenheit. If you don't have one of those then surely a local garage should have one that you could borrow, rent or have them test fairly quickly with it. I personally don't like the idea of an electric water pump because of the whole short limited lifetime that they have. You could be left stranded without a water pump when it fails. Also, if you haven't already dropped in a cooler thermostat try that, and if your fans or fan is not half in the shroud and half out then it won't be pulling enough air through the rad and onto the engine as it should. The old dodge trucks sometimes came from the factory without shrouds and they were pretty bad for overheating. So the placement of the fan is pretty important. So is the blade angle. Check the hoses for kinks or tight spots as well. I suppose you could modify the radiator support to get in a bigger rad as well but more work that way. And finally, I suppose you could even try a serpentine belt setup and run dual electric fans through the shroud. Or better yet, drive really fast everywhere you go and keep the air blowing! Hard to keep the cops off your tail but at least she won't overheat!