The click on every other revolution (or less frequently) is likely a bent pushrod hitting the side cover. It is more of a clunk than a tick. It is easy to check to see if all the pushrods will rotate with engine idling or when not running and the rocker arm not loaded.

If you can't find the source of the sound then use a large screw driver or metal rod or automotive stethoscope. Put one end next to your ear and the other at various places on the engine. You will be able to hear many sounds typical of a good running engine. And occasionally hear a sound that is not normal and be able to pinpoint the location.

Nearly anything that transmits the vibration will work. Just remember the first hearing aids were tapered animal horns. Then granny had one of those metal replacements.

It turns out the number 2 intake valve must be slightly bent because it is the only one that does not turn. It also it the only one that does not have a flat rocker arm surface (dents the feeler gauge). I did have to redo some of my adjustments so now it sounds a lot better.

Since the engine seems to be running well is it better to leave the one valve alone or try to fix it?

Mike