Lifters

You can use a Dremel with a thin cut off wheel to make your own groove. Been doing it for 20+ yrs.
can you take a pic of some of your old ones or provide us a little more info on this mod? Sounds like an interesting project. I liked the EDM drilled solid lifters. a very small hole drilled from the face to the oil band. Direct oil injection to the lobes when splash lube is not adequate. These are hardened so a small .015 drill is near impossible to use without breaking. EDM uses a tiny wire like an arc welder to melt a hole that small.