What is this bolt from

Putting the car back together and can’t find where this one goes. Likely I already put a regular 10mm where it was, but this one is special with the tall head and thin washer. It was rusted on top but not corroded too much, suggesting it saw the salt but also maybe covered with rust check stuff. The other picks are after blasting. It seemed to have rubbery substance around the shaft where the washer goes.




Can you help with what area you were “putting back together”?

The answer to that question is everywhere! This probably came off the car over a year ago with the exhaust/headers, PS, battery plate, intake pipe, some coolant hoses, all engine mounts, starter, all kinds of brackets…Coming down to the end I’ve been able to place everything so far either back on the car or know that it was replaced with something else. This one with a tall head and the end that is untapped suggests special, and I never put one back on the car like that. Racking my brain where it was. Threads were not rusted and the tip seemed uncorroded, so it was either covered or poked into the interior. Having a rusted head would be something under the car or lower half of the engine area.

I know I’ve seen that thing before… Geez.