suburban only grille support

[jonzcustomshop]

I found another unique suburban piece;

my 64 chevy sub has the shear/rubber style radiator support mounts.
I was looking at the old front clip the other day , and noticed these brackets that are spot welded to the grille support. they have little rubber feet that sit just above the bumper brackets, I don't think they touch, I am thinking they are just a safety, or limiter for the amount the front can move.

any one else have them? I am wondering what years they were used, and on panels too?