bumper guard mounting ?

[blazerkid]

so i bought a set of stock bumper guards of another bumper and i put them on and the left one fits and the right one the bolt holes in the bumper don't line up
the driver side holes front top of top hole to the bottom of the bottom hole is 6 1/4 inches apart and the passenger in measuring the same way is 6 1/2 inches what would cause this and why

and my dad thinks that at one time the truck had had front end damage