Looks like a crap shoot to me...
Sign of the times, no other reason. Never have figured out why, if a design has worked for so many years, they change it? Ahh...new and improved...or cheaper. Off soap box.
That Crower cam saver tappet has a small oiling feed hole at the center of the lobe face, or contact face.
I've got the standard type tappets that Crower offers, on my Crower cam. But, not run yet, since I want to change the push rods. Got my own demons!
Yeah, the push rod oiling type tappet is for AMC. Can't say if it hurts anything or not, even if running solid push rods like our motors normally use. If it works, okay, and gets the job done.
One thing, for you, do a search on how an hydraulic lifter works. Easier to deal with if you understand what your looking at. Think of a hydraulic lifter like a shock absorber...one for each valve.