I think that the new ones just aren't quite as big as the old ones...quality control crap
The same thing happened on my 74. Not sure what to do. Can't really tack it in place once it's painted. Not sure if the white PVC tape wrapped on the threads would hold and I don't think you can put a nut on it. I removed the vent assembly thinking I could get to it but I couldn't reach in far enough to start the nut.
Please figure it out so I can add it to the other 1001 thing I learned reading this thread.

