from the 1954 Accessories installation Manual for 1954 cars n trucks

Hole location for 3000 series with or without Grill guard

Locate two holes in stone garde by measuring from center line of truck 20_1/2 " towards the outer ends of the stone guard and mark stone guard. then at the 20_1/2" marks on stone guard measure from front edge so stone gaurd towards grille 3" and scribe centers and drill two 13/32" holes in stone guard, as shown in fig139 (no pic of fig 139)

so no the bumper brkt mounts are not use and they are monted to the front splash apron or "Stone Guard"

These books are kinda neat (get you buddy to buy some) grin
Mike