What would be a good thermostat to run in a 1972 350 chevy?

[franken]

"If the operating temp remains the same with a 195 and 180 stat the cooling system capacity is not adequate."

The thermostat has nothing to do with the final temp of the coolant once the engine is warmed up. The thermostat isn't there and has no way to do anything other than restrict coolant flow and allow the engine (and therefore the oil) to get warm quicker.

This is at least the 3rd time in this thread that someone has claimed the thermostat determines engine temp, which is nonsense.