Thermostat or not

I'd put an aftermarket gauge in it so you can tell exactly how hot it is getting. If it gets hot going down the road, 35mph or faster, your radiator is probably partially plugged or just not adequate. If it gets hot when sitting, then it is probably airflow issues, may need a better fan or shroud. as was stated above, 180 t-stat may or may not help.

First thing, get a gauge that tells the temp, not just hot and cold.