Is it a mechanical or hydraulic cam? If hydraulic you should have no lash, if mechanical what does your cam card call for? How close are you to that number? If the valve is seized chance are it won't move. If actually bent, it probably won't return to closed but it should move towards more open. As a rough guide, take a steel rule and measure the installed height of the spring retainers. That should tell you how your valves compare.