I wouldn't worry about the dent. I don't remember, but I would imagine that is not a sealing surface if the valve hit it at some point? The head gasket sets further out and I wouldn't worry about it at all...
That tube is the pressurized oil from the left side of the block that runs through the cooling jacket to the right side and then up through the block and head and feeds oil to the rocker arm shaft. Mine was not cracked, but it was completely clogged. I didn't take a chance and ordered a new one. It was of course back ordered and I wanted my engine back together so I ordered all the stuff from McMaster and made my own. Then the back order was filled. Sooo.... If you need one, I have a brand new one that you can have for what I paid for it. I'll even through in the shipping for free!
