After seeing that vid, I'm not sure how you'd know for sure w/o touching them off on a grinder. Not worth the risk.
V-block, ball bearing end stop at lifter face center, .0001 indicator to carefully turn lifter while you check face runout. Use to check spindle bearing journals, tapers, faceplates, housing bores, and bearing shoulder runout. No moving parts or runout on a V-block!
I've got some NOS GM lifters sitting on the shelf from years ago. They have black areas on the barrel which I assume is light corrosion. Is there a way to polish them to clean off the areas?