Hey mate, do you have a reason for wanting to pull them out? Is it not functioning properly? Have a read of the post on nissansilvia.com showing some back to back dyno testing of the valves held in different positions. Pulling them out would show a slightly worse readings in the lower rpm's as you inlet velocities would bit slightly lower.
http://www.nissansilvia.com/forums/index.php?showtopic=365186