If the valves are set correctly, and the throttle body balance is good, then you shouldn't have to adjust it. Leave it at zero. If it idles at 1200-1250, doesn't hunt, or smell rich, leave it. If it smells rich, drop it back to -1 or -2. If idle is rough, or hunts, go to +2 or +3. If you have to go more than +/-5 in either direction, something is wrong.