I would do pressed, it's one less thing to worry about. Those sprial locks have broken before and when that happens, you have a wrist pin in the cylinder wall. Not a good thing. Like Sam said, it's a safety thing.
There will be no difference in performance. We have several Z28s in the field that can drive to the track and run in the 13 second zone all day with street tires and closed exhaust. Open headers and tires, look out!
Jerry