Something In my #5 Cylinder?

To me, “locked out” means that the distributor has been modified to never allow timing retard/advance and the timing is “locked” at wherever you turn the housing to. So he’d be at 23* at both idle and 6000.

MSD sells a boost timing retard unit - expensive tho. They’re mighty proud of it.
Correct. It's locked out at 23 meaning 23 at idle and 23 at 6,500 RPM.