Send temperature gauge in to INSTRUMENT SERVICES in MacHesney Park, IL twice or maybe three times and still not correct. John tells me that Ford gauges are 6 volt even thought Ford went to 12 volts in 1956. I was advised to buy a voltage reducer. Got one from VINTAGE AUTO GARAGE in California. Installed it and same negative results. (Haven't talked to these people yet)
Let me add one more bit of information. The engine 1957 engine 312 and the temp sending unit is different than 1956 temp sending units .
Yes, the gauge is on "H" when cold and goes to "C" but before the coolant temperature hits 170, the gauge is all the way over to ''H'' (and it is not HOT, it is only 165 or 170 degrees.)
Tim, Problems are my middle name.
Florida Ford Fan