there's a couple things that concern me on the stainless steel ones and both have to do with where they seal it against the head. One they seemed a little big without much surface between the actual opening and the bolt like I showed in the picture? Also I don't see where they kind of weld bead around each flange for sealing purposes? And I'm feeling if they come off of eBay that my recourse will be much lower than Jegs..