For some reason, I'm guessing this might be your first vehicle with a (real) oil pressure gauge, rather than the 'fake' one that the 6-cylinder GMT360s got?
It's fairly normal, especially on a newer engine. Because of where / how the oil pump is connected, as engine speed increases, pressure goes up (and when you think about it, it is out of necessity - parts that spin / rotate faster need more oil supply).
As the vehicle accumulates a
ton of miles, you'll see that idle pressure decreases. Eventually, you'd see the oil lamp flicker at idle, especially at full operating temp. At that point, you know you're going to be rebuilding / replacing soon.
For a modern GM gas V8 (using your Silvy as an example), that could be from 250K or longer (most people get tired of their vehicles before they get to that mileage); I believe there are people on this site who have gotten 350K + on their motors (both sixes and eights, inline and 'vee'). Some of it's luck; most of it is maintaining it properly. These days, thanks to engineering improvements, "the first" 200K are as easy as the first 100K used to be, from a longevity standpoint - provided they're maintained properly. Good thing, too, considering how expensive new vehicles are.
If the pump fails 'catastrophically' or the pickup tube gets clogged (rare, but it can happen) - you'll see pressure go to '0' in a hurry, and you'll start hearing a lot of noise from the engine, and your dash will likely be lit like a Xmas tree. If that ever happens, shut it down as quick as you can.
PS: Your oil and filter choices are fine. Maybe a little spendy on the K&N filter, but at least you get a nut welded onto the end of it for easy removal...LOL.
