What degree Thermostat?

Speaking from PERSONAL experience,back about 1974ish,I was the proud owner of '71 Duster 340.And as an ignorant 18yo I took the Thermostat out of the motor because I was told I didn't need it !! Well,on a trip from sunny and hot St Creaturesburg Fla. to Conn I started noticing something peculiar.The cooler it got,the colder the therm read.Seemed odd to me,as we were cruising and the motor certainly should have been warmer than what was registering.Pulled over into a service station,explained the problem,in went a 180* therm and I was on my way without any more issues !!My lesson learned,the thermostat was put there to keep the engine at its optimum performance temp,when it reached that,the water would circulate and be again held in the radiator to be allowed time to be cooled !! So there's my .02 for what it's worth !!!