slalom44

Those lobes got wet. I'd guess that there was a coolant leak. Droplets of coolant on the lobes were allowed to sit there for an extended pertiod of time, causing oxidation stains.

When coolant/water is mixed with dirty oil, it forms dilute sulfuric and carbonic acid. These will etch the surface of metals they are exposed to. It might only be a surface oxide that's not very thick but if the coolant/water droplet happens to be between two surfaces (lobe and follower), crevice corrosion could cause it to pit. You might have similar pitting on the bearing surfaces as well.

cvedral

I thought just the same thing just don't see any corrosion any where else, why just the intake cam? It doesnt matter why just gotta do something with it.
Will an ap1 intake cam work ok?