. Many times after 100k they are still within spec. Look at the 350Z it has solid lifters. What does the factory say about adjustments on that? 350Z does not use shims, you have to change the entire lifter. It is too late now, but if you are concerned about wear, you should have them shimmed on the loose side as the valve seat wears it will push the valve stem higher which will make your lash smaller than when it was when new.
