Overheating issues

Check the simple stuff first. Remove the radiator cap. The coolant level should be up to the top of the radiator cap. The cap should have two rubber seals. The small rubber hose should be tight and free of cracks. The recovery tank should be about one-quarter full. Check for gunk on the bottom of the recovery tank.

Was there ever Dexcool in the system?
This is incorrect. The coolant level should be about an inch or so down from the top of the fill spout. This gives room for expansion. If it's too full, it'll only push it out of the radiator cap relief valve.