As Jon mentioned have the radiator checked and cleaned, I'd replace the hoses, fan belt, water pump and the thermostat. Or at least inspect them.
This is the guy that re-builds the hydro valves. I've had very good luck with him.
Machtech Direct
605 Furnace Rd.
Conneaut Ohio 44030
Phone: 440-499-5813
Email:
mark.machtech@gmail.com