exactly, go to a Ford dealer, buy a 192-198 degree Motorcraft thermostat, this is what came in your car from the factory, this will make a difference, trust me. Run timing at 10 degrees, stock headers would help too, if you still have those. Is this a stock MAF and injector car?, if not definetly change back to those. There are products you can dump in your tank, go out and run the bagels out of the car and then go to your test, some say these work, I'm not much for magic potions and such.
Unfortunetly if your cats or cat is bad, none of this will work.
Hope this helps.
