rcdude7, there was another thing I forgot to mention, when I had to adjust the valves on the engine one bank was clean as a whistle and the other one had the black oily mess all over the rocker arm and under the cover too. I'm guessing that bank is the exhaust valve side with the black oily mess.
The black deposit under one valve cover indicates a problem at that location. Check the rocker arm shaft for looseness. I have seen them come loose and eventually destroy the threads in the shaft support and in extreme cases wear a hole in the rocker arm cover.