well this is an easy one lol
if you pop the hood on look on radiator support at each fender on top side there is a round rubber bumpstop mounted, it is adjustable,
adjust them
this is why GM put them there
if the hood wont sit tight on one or both of them then adjust your hood latch mechanism so that the hood shuts down farther- if the hood needs to go down farther on one or both sides- if is higher than one or both fenders*
if you just stop and study the rad support and latch and such you'll see how this all works, and how it is adjustable, its really all pretty basic
another possibility is that the side of the hood that is up too far may be up too far due to worn out hood hinge/spring, but only if the back of the hood is not down all the way also,
if not then its matter of adjusting hood bump-stops and/or hood latch assembly
good luck
