Call Perrin (ask for Jeff
) and complain about the bolt thingy. If it's a fitment issue (wouldn't surprise me), they should know about it. If it's an installation error on your part, you probably want to know.
I got sent the wrong EGT sensor once and the connectors didn't fit right. I was about to cut the wires and use butt connectors but I emailed the vendor and they told me it was the wrong sending unit. Just a thought.