Could use some help identifying some roller rockers

DionR said
@PRH, have you ever seen or setup a Magnum head to run this type of retainer? Thoughts on why it might be setup like this?

Honestly, what comes to mind is……. They were set up by someone who didn’t understand how those parts interact with each other.

It’s a failure waiting to happen.

Edit- In light of the info in post #33, it appears efforts were made to make that combo of parts work(without imminent failure).