I'd shoot for IAC somewhere between 10 and 20, but it doesn't need to be exact. Mine generally hovered around high 30's before I cleaned the throttle body last week, now it's usually below 10. The higher the number, the more the computer is calling for air to keep the idle up. If it's 0, then the idle is not under control by the ECM (air bypass closed) and it may idle higher than 750. Remember, car warm, in park, and no accessories on.