67 Column Mounting Issue

I suppose there may have been something there to keep these blocks from falling out before they got to where they were going
All 67's use the "metal" insulators and the same bolts/nuts/ground wire, what is the problem?
Sorry, I should’ve been more clear. The problem I’m having is that the insulators fit on the bracket very loose. There’s nothing to hold them on, and they just slide off. I’m not able to mount the column solidly.