Ticking problem solved!

I finally got tired of hearing the ticking and decided to do something about it. To anyone who hears a metallic clicking in time with the valves opening and closing--check your lifters! I found two of mine had worn on the bottom where it contacts the camshaft had worn concave. A new set of lifters later and the XJ purrs like a kitten again. If you have the same problem I did, take off your valve cover and start the engine. The push rod at the worst lifter was shooting oil all over the bottom of the hood and over my A/C lines.
Anyone have any ideas on what would cause them to wear that badly on a 2000 with 88k on it?

Another tip for other newbies--be careful with cheater bars on your ratchets. They hurt when they slip off and hit you in the face.