At around 60K Km the cams in my 2001 were badly pitted, every lobe. I replaced them with used cams from an '86 with around 72K Km and no pits.

Today at 71K Km, first valve adjust after replacement. No pits! Minimal changes in valve lash.

The moral of the story, Ma Kawasaki did a better job on heat treating the cams earlier in the production run. Later on she found she could save money, skip the heat treatment, and they would last longer than the warranty.

you're probably right, at least that the early cams were made better. I see alot of cams in my cam exchange program, and really, the early ones are always the nicest and least pitted . steve