95 Mustang timing

I a have been having problems with my 95 Mustang with overheating (with the AC on, mostly). I have done everything (changed water pump, thermostat, hoses, flushed and filled, ran rad cleaner through it) with no success. A guy at work suggested the timung might be retarded. Can anyone give any suggestions on setting the timing? Thanks

You need a timing light to start with. I your car is supposed to be set at 10* advanced with the spout out.