Okay, kids, here's where I ended up:
Ford Motorsport 351/400HP. Factory installed 192 degree thermostat, factory installed bypass hose from thermostat housing to water pump. Standard rotation water pump. This engine ran for 20 minutes and did 2 dyno pulls at 200 degrees, according to Ford's data sheet.
I installed a March pulley kit and bracket, and the pulleys are NOT underdrive. The belt runs only the alternator and water pump, just like Wayne Presley's setup pictured in my initial post. I also installed a plug on the water pump heater connection.
I am absolutely sure that I have all the air out of the system.
Today, I removed the thermostat and gutted it. I removed the entire spring and disc assembly, so it's effectively no thermostat at all, but with enough flow resriction that I won't get cavitation or excess velocity. I also installed 1 gallon of antifreeze to improve the boiling point (should be about 25% now), and 1 bottle of Water Wetter to improve heat transfer. I also decided the belt was too loose, so I tightened it.
The temperature here today is 50F. Once the car was running smoothly (no choke), I set the idle at 1500RPM and let it run with the cooling fan set on contant. Over a 25 minute period, the temperature slowly and consistently increased to 215, wherupon I shut it off. At no point did the temperature ever rise and fall, which would have been indicative of air in the system. It went up at a constant rate from 70 to 215, and was still rising when I shut it down.
Can I now safely conclude that I need a larger radiator?
"Loyalty to the country always. Loyalty to the government when it deserves it".
Email joseph.leone "at" comcast.net