I'm going to New Haven tomorrow to look at a B16Sir head. A friend of a friend is selling it. It has all internals except for the cams. And the guy claims that the head is upgraded with Skunk valves, springs and retainers. The problem is that I trust no one. Is there any way I can tell if he's lying or not just through visual inspection? Any characteristics I can look for to identify them as genuine Skunk parts?