I run a 160 thermostat and 0 pressure radiator cap wih an overflow reservoir and my 49 216 stays on the "8" of 180 in the gauge spring, summer and fall. When I open up flow to the heater core in the winter it runs a little cooler, normally it stays on the "1" of 180 on the gauge.
It will climb alittle higher on extended idling and drop with more air flow through the radiator when moving, but never over the "0" of 180 on the gauge.
Try a 160 thermostat...
