I am just asking here ARE YOU SURE you know your bolt sizes? The bolt size that fits those hoods uses a 1/2" wrench. ONE HALF INCH WRENCH. That is the standard head size for a 5/16 USS bolt. A 5/16 bolt is not "damn near 1/4 inch around" that is, a ONE QUARTER inch bolt is "1/4 inch around."
I'm just askin', OK?
Here's the possibilities:
1....You need a 5/16 bolt with a 1/2" head
2.....You need something larger (unknown) because as OldManMopar said, someone may have tapped it larger, (was stripped) or used a helicoil repair
By the way NOBODY on here likely knows more than Steve, OldManMopar. He KNOWS his stuff.