[FlatheadTed]

Its best to have a radiator (as you have ) that is more efficient than what's needed ,then the thermostat keeps it up to Temperature by opening and shutting .The temperature starts /or wants to rise when sitting in a parade or at traffic lights ,the thermostat should be fully open at that point and the fan should start lowering the Temperature ,From my experience more than one hole in the thermostat will give a slow warm up .