Wouldn't changing the thermostat to a 180 help with the baking of oil in the heads? Or would that throw "out of whack" all the temp controlled electronics..
If you put a colder stat in the computer will tend to run it richer, it thinks it's cold so although performance may be up just a tad fuel mileage will be down. Cylinder head temp is not just dependent on coolant temp. Think combustion chamber temperature. So not much help there.