Scott, that head has been sitting out under my shop's lean-to for about 6 months, so yeah, it's filthy. As I said, I replaced both heads... the pic is of the old head that had the loose exhaust valve guide. I just kept them to practice welding on. That's not a hole, I think maybe a tiny spider web. On these Kohler Command Pro heads, the valve guides are pressed in at the factory while the head is really hot... then it shrinks down to clamp them in. So you can't replace the valve guides... just replace the whole head. I have not removed the new heads as I feel they are probably fine as the leak-down test is good. Thanks for the reply.