Doing some maintenance, pulled off valve covers one at a time. The passenger side (done first) looked great, all rockers and hardware was a nice golden brown color, all the way across. Now I'm on the driver side and the rockers toward the front look very dark and have some sort of sooty looking deposits all over them. Bolts all the way to the front (left side in picture) look dry, no oil on them like the other bolts. Could it be these are being starved of oil? Gosh I hope notů
Btw, she has 223k, runs amazingly well and strong. However going up hills and under hard acceleration I sometimes hear clatter from the top end of the engine. Kinda sounds like it's on the left side when driving. Can I blow compressed air into the oil supply holes on rocker ends to clear out potential blockage? I'm really not familiar with the lubrication system on this motor.
Keep in mind that the PCV system sweeps 'dirty' blowby air from everywhere in the crankcase to the front driver's side corner of the engine where it gets pulled by the vacuum forced thru the PCV valve thru a channel along the length of that valve cover. For that reason, everyone generally reports that area looking much dirtier/blacker than the corresponding areas on the passenger side.
That doesn't mean that there isn't something else going on that additionally explains what you're seeing.