This is embarrassing. Replaced a water pump on my 88GT 2.8L. While I had everything out I also repaired the rusted and corroded battery tray.
Work got in the way and some time passed.
Now I've gotten everything reinstalled and am putting the battery back in. I have a small pointed bolt that I had labeled "negative ground wire" which I'm sure goes to the pigtail lead coming off the negative battery cable. I just can't for the life of me remember where the bolt screws into.
[- 88GT 2.8L -]