68 ss hood scoop

I have a 68 ss Cuba/Dart hood scoop that I'm getting ready to install. I noticed a slight sag on top (about 1/4" deep) from front to back. I Think it's somewhat common, but I would like to straighten it be fore I install it. Any ideas on how to do this? I was thinking of glassing in some small angle iron ribs under. What do you guys think?
Thanks, Joe.