Don & EB-
Many thanks for posting the specs and sharing your knowledge. Looks like I have a couple of parts to order ASAP as I was supposed to take the pony over to the shop today for final tuning- that will have to wait until I get the right parts in. (I'm going with option 1, as this is going to be a daily driver)
Napa #197= 180° thermostat
Napa #297= 195° thermostat
or I got my 195° one online from Amazon:
http://www.amazon.com/gp/product/B000C809CY/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
Original Robertshaw specs:
Specs on thermostat I got through Amazon(If you convert decimal to fraction, the dimensions are virtually identical:
As far as the brass bypass washer, I hear you can get them on ebay. Here's some other info I saved which may help:
Yes, those are the two main options. Each of which have some other considerations.
The #1, stock set up is the most "dummy proof" but it all comes down to you having to rely on a $10. part. The thermostat must work correctly for the factory internal "Controlled Bypass System" (as Ford called it) to work. Brand new thermostats can work incorrectly, so if you're gonna go this route, test your thermostat for proper functioning.
The #2, "Pantera set up" will make your engine take longer to warm up to the temperature it was designed to run at. Some people think that if your not overheating, all is good. Underheating is also not good, it's just not as obvious. If you like to run your car in the summer without the heat on...I'd caution you. (who the hell wants their heat on in the summer?...you ask) you're already working without the internal "Controlled Bypass System" by going with the #2 option. The heater core loop also works as a bypass loop (shortcut around the radiator) while the thermostat has yet to open. With both possible bypasses closed where does the water pump get it's return water supply, prior to the radiator loop being opened by the thermostat?...it doesn't have one. The coolant in your heads is not circulating (or going anywhere) if it has no where to go to. To remedy this, the more learned/experienced guys will drill a "few" 1/8" or 3/16" holes around the perimeter of the thermostat. This will allow "some" water to circulate through the radiator, providing return for the pump to pump. Two 1/8" holes for stock hp motor to 3-4 3/16" holes for a high hp motor. (get the picture?) Again, this option will take longer to heat up to operating temperature, so if your constantly using the car for 1/2 hours runs and it never gets any hotter than 140°, you will have other problems and will NEVER TRUELY EXPERIENCE THE ENGINE'S POWER POTENTIAL. There are way too many variables to consider which is why the Ford engineers came up with #1. Test your thermostat.