I’m shocked at how thin the bottom of that lifter is.
That’s not worn nearly enough to end up with a hole in the bottom imo.
Be interesting to compare the thickness of an old OE lifter vs what you can buy now.
Edit......
I have some Crane BB hyd lifters from about 30 years ago here, and some solids that might be a few years newer.
I took them apart, and there is a small counterbore at the bottom of each.
The area at the bottom of that counterbore is only about .125” thick on the hyd lifter, and maybe .015” or so thicker on the solid.
That’s only for a small circular area right in the center....... where the hole is in the OP’s pic.
The area outside of the counterbore is about .040-.050” thicker.
I don’t have any “new” lifters here to compare.
