Are you taking about the 3 j clips that hold the rear of the dash board top down under the front windshield ?
Those 3 clips attach to the metal section of the dash top with the vin number, when installing the bottom of the j clips slide into dash board frame and hold the rear of the metal top down.
There should also be a foam pad around each clip to stop the metal on metal rattling.
Depending on if you have a 71-72 then the front of the dash top with the pad gets 2 long screws through the center panel, and 4 more screws held on with clips to the ends above the glove box and main instrument cluster.
The 73 used 2 more screws under the windshield to anchor the dash top.