This is one of 2 or 3 that runs down the center of the valve cover.
These are used to ground the coil packs out and would have an 8mm nut on top.
Feel free to reach out with any questions or concerns you may have.
I will include the 8mm for your convenience as well as washer and grommet as pictured.
Thank you for viewing and please see my store for the many vintage and newer parts coming online this year.
Cheers to good health!