Any Pontiac guys on here? Need insight.

First.
Post #107 is incorrect. The disc meters oil through the p'rod to the top end. What 'shuts' up the lifter is the valve at the base of the inner piston. not the disc.

Second.
The flat disc with 4 holes in it in post # 108 is used to meter oil through the prod. But how can get through the holes to get the hole in the prod socket when oil pressure is forcing the disc against the prod socket??? I am 99% sure this is how it works. With a hyd lifter, the lifter bleeds down slightly as the lifter rides over the cam lobe; this creates a gap under the prod socket & oil gets pumped through the 4 holes, into the prod socket, & into the prod.
Sol lifter, it has the lash clearance, works the same way.