[Gearhead999]

Car shouldn't overheat with 180, or 195. You have more problems then little heat.

With a 160 thermostat the heat temp will be on the COOL side. The temp. sender is only the sending unit for the gauge. Has nothing to do with the actual temperture of the engine and the amount of HEAT you receive from the car.

I'd find out why it overheat with 180 thermostat.

First thing I'd check.....If the heater core was "full of crud" then the radiator might be too. If it is this will cause the car to overheat.

Hope this gets you in the right direction.