I just came across this site that cross-references GM hardware part numbers by sizes. This is a great resource if you want to replace factory bolts with something else and need the sizes.
Hello, I am in the process of putting together a 1957 p/up. It was a basket case and I need the bolt sizes for the front sheetmetal. I am using black chrome and they do not sell in kits. They are also expensive so I don't want to order too many extras.I want the bolts that show to be black...