Chevrolet Repair: 59 Chev Belair temperature gauge, radiator cap, gauge reading

Question
my original in dash temp gauge is inaccurate. As verifed by an after market temp gauge the original gauge reaches its maximum reading when the water reaches 160 degrees F. The original gauge reading rises evenly as the water temperature rises until at "H" it can go no further. Engine has a 190 degree F thermostat and will run at 180 - 210 degrees depending on conditions, has a 15 pound radiator cap. If I disconnect the wire to the sensor in the block the original temp gauge does not move off "C". Thanks, John

Answer
what is your question?  This is just information.

you probably used to run a 140 f stat.  today we realize that cars are more efficient around 200f.  The guage range wont reach these temps.  get a new guage and try to switch the face with yours.  Not original but operational.