Oil pressure gauge drops from 60 to 20 while idling or if I’m off the accelerator, is this cause for alarm?

Oil pressure gauge drops from 60 to 20 while idling or if I’m off the accelerator, is this cause for alarm?

I'd say that's normal when engine is warmed up/hot, especially if you have 5w30 oil.

As long as it's only 20psi while idling, I wouldn't be too concerned.

20 pounds is fine at hot idle. GM's states approx 10 pounds for every 1000RPM, so you should be fine.