Roger, you bring up an interesting point about clutch fans; I was going to start a thread in the Heating/Cooling Forum on the subject but this is as good as place as any. My understanding of thermal clutches is that they lock up when the air temp elevates, and free-wheel when the temp drops. So in stop-n-go traffic, airflow is diminished, temp goes up and clutch kicks in, turning the fan. My original fan was direct drive so it was spinning all the time. So everything else being equal, just adding a clutch will not improve low-speed temp creep because the fan is spinning in both instances. The benefit of the clutch is at highway speeds with reduced drag.
Then there's the fan itself. I agree that it seems 7 blades would draw more air then 5. But then there's the width and length of the blades, and the pitch angle. The way to test the theory is to install a Mopar 7 bladed clutch fan and note the temp.
Side note: last night Maria and I cruised around for an hour after work. It was still over 90*, pockets of stop-n-go traffic. On the highway, still hanging around 185*. On surface streets stopping at some long lights the temp got up to 195* but would settle back to 188 - 190 after just a couple of blocks of cruising. So for now the car is running cooler with the new setup.
