A cautionary tale when working on push rods

That style of pushrod cup retainer is very easily damaged.

One of my customers had that style of lifter in his Pontiac........ over revved it a few times.
Had the intake and valley cover off at some point afterward, and about half the pushrods had those clips flopping around after the valve floated a little and in the process the pushrod “stepped on” the clips....... they folded up a bit, and came out of the lifters...... and were just riding around on the pushrods.

My preference for hyd lifters where valvetrain drama is likely to occur are the ones that use the “tru arc” style of internal snap rings.