Originally Posted by Sin7
Here in a bit I'm gonna pull the header off the head to see what 4,6, and 8 look like....
Be back shortly...
The black stuff you are seeing is most likely due to a bad header gasket. I think in an earlier post you said you had a loose header bolt. That will quickly lead to a blown gasket.
Do you still have the original valve covers, if so pop them on and see if the issue goes away. Your issue sure sounds like the PCV is sucking oil due to lack of proper baffles.
At this point checking the plugs isnt going to tell you much, you already know oil is getting into the cylinders so at least some of the plugs will be black.