Pilot, you'd have to get so lean to burn a piston that I doubt you could live with the driveability issues. I have tuned primaries several ways. I've used the old emissions machines garages used to use....I'd run up the RPM and watch the gauge. I've used an O2 sensor hooked up to a voltmeter to read the Oxygen percentage on the exhaust and that's super sweet . You can see what is happening to your curve as you drive. Or, you can trial and error. Just lean the jets down ( stay out of the secondaries!) The idea is to just use light throttle, steady-state driving on a highway. If the car surges slightly, you're too lean. Go up a size and retest. If the surge is almost gone, go up 1 more size. You are now as lean as the engine will tolerate and still drive well. Use the secondaries to give you max HP, the primaries for max Mileage.