OK - I finished my science experiment and mapped out the resistance vs temp performance of the sending unit p/n 1233-4869. For those interested in the calculus, the best fit curve was:

R(T) = -230 + 25549 / T^0.81344

in words, this is the resistance (ohms) as a function of temp (deg F) is -230 plus the quantity "25,550 divided by the temperature raised to the power of 0.81344"

So next I will run the engine and take a resistance reading when it is warmed up. Hopefully it will be around 150 Ohm, indicating a temperature of about 180 degrees.

Sorry for the math, but I am an engineer...

1956 3100