Hi Phil,
I had to have a head (glow plug hole stripped) for a Fox 40 Stunt ('70s version big case) so I robbed one off a NIB one I had. Of course, I wanted a new one! It had only been a couple decades since they made them......... So, I called Fox and spoke with an older gentleman in parts who came back and said he had one in his hand! I had no parts number, etc., but it was the right one. Now I still have a "NIB" Fox 40!
Give them a call.........
Bill <><