Picture of the lifters shows the feed hole for the pushrod oiling is drilled in from the side which is correct. Many of the lifter mfgs drill from the bottom which doesn't work. Not sure why some folks continue to build parts for 30 years that don't work but they do.

There is also a small EDM hole that feeds the roller. It is too small to see but it comes in off of the relief area so it should get full oil pressure all the time.

I haven't measured yet to see how much lift these can handle before exposing the oil gallery but I think it is probably a bunch.