RockinWs6

I wouldn't worry about it. I've seen the same many times and usually it goes away. Probably lifters.

68shortfleet

I have the same issue.
Bouncy/twitching needle at idle with 35-40 psi.

Autometer mechanical guage at the stock location behind the intake manifold.

If I move the guage to the bypass block above the oil filter, Pressure is slightly better and the guage needle is steady.

I'm suspecting cam bearings. Lifters, rod and main bearings were just done.