Mechanical vs hydraulic valvetrain

It's a learning process. No need to act like any stupid questions have been asked. They have not. It's all good. That's not very much sludge at all. I've seen them so bad that you cannot even SEE the rocker arms. You can clean that up by dumpin a can of SeaFoam in the crankcase and running it for an entire oil change. That will likely get it clean. SeaFoam is some good stuff.