Update - fifth time adjusting rockers to chase it down. Discovered that cylinder #8 rocker nut polylock doesn't go in the nut as far as the other 15. It sticks out of the top of the nut 3 threads instead of sitting inside it by a couple threads. Meaning the rocker is sitting lower than the other 15 rockers are due to the PR
To me, that says 'collapsed lifter'. Anyone else?