'56 Belvedere 4-dr sedan, rubber on valence or gravel shield

[dickf1976]

Just had car painted, including valence and rear gravel shield. Before attaching rear gravel shield I want to attach a strip of "separation" rubber, but can't remember if it attaches to the valence or the front edge of the gravel shield -- or is it the rear edge of the gravel shield and meant to keep gravel from getting between bumper and gravel shield, in which case how tall is it? thanks in advance