"Also worth checking if the cams axial play is correct, if the cam is walking back and forth tapping the end plate it also produces noise and influences cam timing.
"

Yes, yes...!! and, how do you set it? I asked about this subject in this forum & got no repsonse.
I figured shims from some small differential, placed between the brass plate the the cam nose-step.




And yes, I found the same issue with factory geometry, as if they set it up for the A-cam and never revised it for the later cams.

As far as rockers, I'd like to hear from John, if, and if so, why, he dropped the rocker thing. I know for a fact they are still available, so supply wasn't an issue... He was a strong proponent of them for many years... As a point of respect (tragically unrequited at times), I generally have avoided discussions of how to duplicate his efforts.