I was looking for the same piece. I went to a ford dealership and they didn't have a part number for it, or any idea what it was. He looked at a diagram on his computer but couldn't find the part. Bill Jenkins can get them pretty cheaply. Just gotta wait a while because hes often busy. Mine broke, and I used a slightly bigger o-ring on there, to keep it snug and sealed good. No problems or leaks at all.
