Read through this thread and thought I would share my story. Back in early 2019 I decided to upgrade my camshaft on my 2002 Tahoe along with some other goodies (roller rockers, upgraded heads with new double valve springs, exhaust, new oil pump (the list goes on) and an updated BB tune). The Tahoe had about 220K miles on it. In the process I dropped the pan and replaced the o-ring and pickup tube. I absolutely loved the added HP/torque. Spring ahead 55K miles (Feb 2021) and I noticed my oil pressure dropped off to 20-25psi while at idle and around 40 psi while driving. Direct reading gauge indicated the same thing. Spent some time troubleshooting but not really getting anywhere - thought I was going to drop the pan again and maybe replace the oil pump. The engine was still running very strong. After another 4K miles, I was getting and intermittent knock sensor code. Of course I changed these out (AC Delco) along with the harness (not A/C delco) during the upgrade project. So now I'm thinking, I should have used a better harness. So, I started procuring parts (gaskets and such) to tear this thing back apart. Another couple thousand miles after riding it a bit hard, I noticed a very slight knock. Drove it back home for more troubleshooting. Sounded like lower end. Drove it to work the next morning and the knock was much louder and the oil pressure dropped to near zero at idle and 30 or so while driving. Big issue. Decided to get a new engine which I upgraded (she's currently around 400hp). Dropped it in, BB provided me an updated tune and man she runs great. Took the old engine apart, and sure enough I had two absolutely destroyed camshaft bearings. The crankshaft bearings and main bearings all look pristine. So, cause and affect, which was it. Was it the low oil pressure that caused the issue or the camshaft bearing that caused the oil pressure. I tend to lean toward the camshaft bearing. My only regret - I should have dropped a 6.0 in it.