Just how thick are the bumpers? How about cutting them down? I measured mine and come up with about 1/2" thick. When the hood is closed I have about 1/4" gap. I can't figure out what sheet metal your bending? If you have to slam the hood so hard it's hitting the bolts, then I'd go back to the hood alignment/adjustment! Note, a properly adjusted hood moves rearward and down when latching.