Unfortunately, not all of us have a Ford Dealership like Mel does either. I'm sure the stat through my dealership would be $20 more than the +$20 Mel mentioned. The parts guy at ours, is such a jerk, I just don't go there, in fact, the one I got came from Titus-Will which is about the only dealership I deal with. I sold Stant products for years though and know they make a quality product and may well make the one Ford sells as they do make many OEM parts as well.
Something that I do on ALL thermostats I install is drill a small hole in the flange. I've done it in every thermostat I've installed in the past 20 years, which having worked in three different garages (ran one in the day, worked in two others in the evenings) that's quite a few. I come just inside the gasket/ledge area and drill a 1/16" hole. If the thermostat sits horizontally, put the hole on the top. Some already have a "jiggler" in them that allows trapped air to flow, some don't. The hole is too small to affect operation but will let trapped air bleed out. You may or may not agree with the process, but I've never had an issue and they've always worked well. It's my thought that the factory should do it anyway as it's worked so well for me.
If your not familiar with an airlocked thermostat, it's when an air bubble gets trapped under the thermostat around the element that heats and opens the stat. The air never gets hot enough to transfer enough heat to the element, therefore the stat never opens and overheat occurs.