Yes the single wire Temp sender needs to have bare metal threads on the lower part only so the "red" stuff won't hurt anything
Sender needs to just have the one terminal if used on a one wire vehicle, if you see two terminals on sender then it won't work
Remove either Heater hose at the firewall and then refill at radiator, this will let all the air out of the engine side, so no air bubble
Coolant should run out of removed hose end and its heater core tube when all air is out, put hose back on and top up rad
For temp gauge Ford has 205degF as the 1/2 way point
Warmed up engine should be just below 1/2, 190degF
On cold start feel the heater hose and upper rad hose, should be same temp of course
Set cab control to Defrost, fan off or on low
Let engine idle for 2min
Feel both hoses again
Heater hose should be warming up
Upper rad hose should still be cold, no change
If upper rad hose is also warming up then thermostat is bad, stuck open