I pulled the lifters out of my 97 LT1 with 70k miles, good oil pressure, and no funny noises. Circled in yellow is what I spotted. There appear to be grooves worn into the lifter, some of the other lifters are smooth, some are slightly grooved, but this was by far one of the worst. The bores appear to be ok, I haven't check the cam lobes for excessive wear yet. Thoughts are welcome. Should I be concerned about this?

 

Weird. That part of the lifter body touches nothing.