Does anyone know if all the engine temp sending units are calibrated the same or are there different ones that have specific operating temp ranges for specific car models? Got a 71 B-body w/440 HP motor. Gauge always reads hot but the radiator, water inlet, and radiator cap all read approx. 160-170 degrees. Hottest temp recorded anywhere on the motor (except exhaust manifolds) reads 190. Gauge is fine w/new solid state voltage regulator. Everything else check out OK.
THANKS

I believe there is one for gauges and one for idiot lights.

Thanks. Do those temp reading sound correct for those locations for a normal running engine after driving for 45 minutes even if the temp gauge reads hot?

My 340 gauge shows it is running hot but when you check it is only around 190 so the gauges are not always right. Ronnie

All but a couple of readings were in the 170 to 180 range except a couple that read 190. I used a laser thermo gun to check.
I rigged up a spare Mopar temp gauge to the sending unit along with a spare voltage limiter and both gauges read the same (hot). I changed out the thermostate to a 160 and that helped but eventually the gauge read hot after about 45 min of city driving. When I first start the car the gauge stays below the mid point for quite a while but moves from the middle into the hot area quickly after that. It tends then to stay at the first hash mark on the hot side of the gauge while driving in the city but has never boiled out. I haven't taken it out on the highway yet but plan to this weekend.
Suggestions?