so as the book says its the highly defined mark on the left side and the mark on the right side is the the almost looks like casting mark. thanks for the photo. I saw a picture on ebay from a firm that was selling a pictural view of the parts on the engine and how it all goes goes together. it showed pretty much the same thing. seems it would be a lot simpler to put this in writing for us new comers to the german world of automotive engines. now on to the cold start valve! Thank you for the help.