Take the time to do a waterpump, thermostat, fan clutch, rad/heater core flush, rad cap.

My totals parts bill from Napa was just over $180 for everything including new hoses and coolant.

It takes 5 hours if you work at a snails pace with beer breaks. Just do it. You gain a cooler running engine, peace of mind and knowing it was done properly and confidence/experience. Any backyard mechanic can do this with a basic tool set, i promise.

Life is to short to worry about over heating.