What goes through this hole in a '69 b-body (Plymouth) ?? Right above the throttle cable hole.

the hole on mine was a lot smaller and that's where my ground wire is attached

Plastic push-peg hole for the firewall insulation?

Ground wire was up near the seam and on the other side.

Not a push peg hole - those holes are all dimpled out. This one is flat.

I have a whole bunch of reference photos but wouldn't you know that none are showing this area !!

pretty sure the ground goes there and someone made your hole larger. probably should have phrased that differently......

Hmmm ... note where the grounds are ...

hmmm.... you seem to be right! well, for what ever reasons mine go to the spot where you have a much larger hole. weird cause my hole is threaded to take that same bolt.

As John Kunkel said it is a push pin for fire wall insulation.

I want to add a picture but wtf I cant figure out this new system???????????????????????????????????????

Here is an interior pic.

Huh ! Ok, can't argue with that. All the other push pin holes are dimpled but not this one. That was throwing me off. Thanks.

the push pin theory makes more sense than my ground wire but the hole is way to big now.

All those push pin holes are getting flattened and filled anyway - as are most others. Cleaning things up a bit !!

Well after taking another look there's no doubt that at one time it was a push pin hole which I must have enlarged to run wires or something through (maybe an oil pressure line). But since I've owned the car for over 40 years, I just don't remember!