I'm not jumping on one side or the other of this debate but just throwing out my personal experience. Old setup was a standard water pump and 5 blade fan. Car ran around 180-190 most of the time. Now with an electric water pump and no thermostat, it runs around 190 with the electric fan on. I tried a restrictor plate and it actually made the car run hotter. I couldn't get it off 210 degrees cruising on the higway, even with the fan running. Took the restrictor out and it runs cooler again.
Now, to give you an idea of how fast this pump flows. I was flushing the whole coolant system the other day. I was going to run a water hose in the radiator fully open from the faucet then turn on the pump. The idea was to turn the pump on, let the water hose feed water, and the upper radiator hose I had routed to a pvc pipe going out of the system. I filled the radiator and put the hose on the ground so water wasn't spewing everywhere out the top. What I would do is lean into the car, hit the pump switch, and go grab the hose and keep feeding water and get everything good and flushed. Well that was the idea. I hit the switch, ran to the hose, and by the time I grabbed it, the pump was alread done pumping all it could get. This was literally about 2-3 seconds! No exaggeration. Next time I kept the water hose feeding the radiator before I hit the switch. It still only took about 3-4 seconds to pump what it could get. What I was getting out of the hose compared to what the pump was doing was a joke. It is a serious pump! My mind tells me it's flowing WAY too fast, but the restrictor plate made the temps much worse, opposite of what I was expecting. I personally believe it was aeration caused by the restrictor plate, which resulted in less surface are in the coolant across the radiator, but I'm not 100% sure. I'm still looking for a better solution to slow the flow and won't aerate the system. I don't see any reason it shouldn't cool as good as before or better. Just my experience.
