I have a 68 F100 that I'm restoring and I'm missing some fasteners. I can locate them on the Parts Illustration image and then when I try to look the part number up in the Master Part Book under that section and main part number sometimes the fastener number it listed and it has a description. Example: Part Number 378178-S, Description: Screw & washer assembly, 5/16-18 Thread, 1.00" long, medium silver zinc plate finish. Sometimes the fastener number is shown on the Illustration Image and not in the Master Park Book under that section and main part number. All you have is a number. Example: 380104-S, 42127-S, 372158-S are part numbers that are only listed on the Part Illustration Image and not in the Master Part Number book under that section and main part number. I have looked up some of the numbers on AMK Products website and a few are listed. Is there a way to decode the part number or is it just a generic hardware number.