Did it just start overheating? or was there something done to the car then it started?
First of all bored 30 over will make it run hotter.
Mentioning a colder thermostat might help. I can't see how that would help. once the thermostat opens it's open. You might have one that is sticking.
timing could be the problem.
One other question are you running hot or boiling over?
Also you might check the radiator cap the seal might be torn. what is the lb cap your running?