Removing the secondaries without resetting the lower fuel tables will invite a lot of deceleration popping (overrun backfire). If you want to do it and not sound like Orville Reddenbacher is holding a mega-concert in the engine bay, get a Tuneboy. The PCIII does a very good job of fiddling mix but has limitations beyond that because it goes in AFTER the factory ECM (takes ECM output and adjusts the signals to throttle bodies and fuel pump). Tuneboy reprograms the ECM directly. You can raise the redline, adjust the ignition maps, perform diagnostics and spend countless hours wondering exactly how you destroyed your engine (something a PCIII just can't do). I did mention "risk/reward" didn't I????