I have questions, no answers about the cooling system

[Calicat]

Here is the thread with the temp sender data. Royce tested an OEM Motorcraft C6DZ 10884-B / SW552 NOS part (correct for a 67), Calicat and 70XR7Tom both tested an OEM Motorcraft D0WY-10884-A / SW924 NOS part (correct for a 70 351C). All three measured around 22 ohms at 212 degrees. Looks like Ford intended the temp gauge to be centered at around 212 degrees coolant temp. As Royce and Bill both suggested, Shurley might have an aftermarket sender that reads too high at normal operating temp.

Pet peeve - part store temp sensors

For some reason people feel compelled to replace everything they can on our Cougars with cheap crap from the auto part store or shoddy repop parts that cost a lot but don’t work right. I commonly find that old Ford products have temperature gauges that read too hot when in fact the car is not actually overheating. The replacement sending unit is simply not calibrated correctly. I just removed probably the 25th one that I have found with this problem and decided to document the differences. The…