408 Valve train noise??

This is a hardcore answer, but I think people get spoiled by how quiet our new cars are. So, you pull a valve cover and check to see if its hurt. If you find something, report back. If not, run it. If it eats itself, it’s under warranty. My hyd flat tappet was noisy, wasn’t happy with it, but ran it for a time. Decided to go solid flat tappet. No more hyd for me.