Yes, I have checked the oil on the dipstick and it's on its maximum level, maybe a mm below, has it enough.

Yes, of course Chim, you suggested that in the first posts when I opened this thread, not yet changed the oil and filter and that will be looked primarily, hope it is to see and confirm with the snorkel camera.

When I apply the brakes hard suddenly during the drive regardless of my RPM of engine in that moment vehicle stops very quickly and the needle from the oil pressure gauge on the dashboard moves from 20 PSI to zero and then appears Check Gauges Light and after that bounces to over maximum level on the cluster and returns back to minimum zero level PSI at stays in that position until I continue to drive after stop on traffic lights.

When this firstly happened on the vehicle, I was in some mountainous racing with some cars in high RPMs with lots of downshifting and frequent gear changing in 3-2-1 mode on automatic transmission and when I stopped at the gas station, I saw the oil pressure Check gauges light appear on the dashboard

 

I have not had that problem of losing oil pressure during aggressive driving through canyons. There are aftermarket oil pans with baffles and flow traps designed for hard core auto cross use but I have never needed that type.

If your windage tray was removed than oil can foam as a result of the crankshaft spinning resulting in low oil pressure. Often on 383 builds, like mine, they don't put the stock windage tray back in which results in this. I just used 1/8" washers to space my windage tray away from crank on that motor. Your stock motor has a windage tray which you would see with the snorkel cam

Its rare stock oil pumps lose their oil pickup but guess it could happen. Typically aftermarket oi pumps that do not have bolt pickup on but have pressed on pickup on them can come off. I braised mine on before installing it

You need to drain your current oil for analysis so just look with camera before you refill it. Try 10-40 if pickup is still on and see how much oil pressure improves.

Blackstone Labs advises to send a sample of oil when engine is at operating temp but wait until about a quart drains then take the sample. They only need a few ounces of oil and have a container you put it in to mail them. I understand your location makes this unlikely as you are using a local lab to analyze yours.

 

I have a stock pan and everything other except removed cats inside precious metals, everything other is on its place as far as I am concerned.

I will inspect it exactly as you said Chim and look for a windage tray with snorkel cam, there is no better solution than this one.

I think nothing has changed about the oil pump and pickup while the car was at previous owner, my friend, never mentioned me the change with the oil pump and other things, visually looks like the oil pan never removed before.

Okay, I will try that with the other oil gradation, but I doubt in oil last time put in, I will attach the picture just to see, I think it was the whole bad batch of this oil from the supplier

Thanks a lot for sending me your picture of oil analysis from the Blackstone Labs, so now I am better informed about what they do in their tests, so can forward that information to the local lab in my city where the analysis will be done