If both metal surfaces are really smooth and you have a good composite gasket then you may not need it. - If you have a good gasket goo available, it can't hurt. -My favorite is 'Permatex Aviation Form a Gasket' .
You should use a thermostat gasket along with the thermostat housing ring. The gasket should be replaced every time the thermostat housing is opened.
On some of the older models (4-5 years or more) most mechanics use a light coat of gasket sealer to hold the gasket in place until the gasket housing is torqued down. Some thermostat gaskets come with a gasket already coated with a peel off to help hold it in place. On most newer models they use a rubber "O" ring or seal and no gasket is required.
Tools a new thermostat and gasket and coolant
Vehicle will run without a thermostat - however will not run as efficiently and will have not heat
the location of the thermostat is under the throttle body.before you put it back on you need to buy some gasket sealer or a gasket for the thermostat
You will need a new head gasket if you see engine coolant in the oil. I don't know about the thermostat.
want choke thermostat GASKET for 1971 Plymouth 225 cu in motor
gaskets exist to eliminate the need for adhesive, you do not need to glue them
There's a gasket between the thermostat and the block that you need to replace.
yes
Most definitely... If you don't and the thermostat is bad you will over-heat the engine and the gasket may leak or warp the head. Thermostat is a lot cheaper than tearing down the engine again.
No , there is a rubber ring that goes around the edge of the thermostat