Hello.

It would be a Shelby part number for the 68 hoods, which is S8MS-16612-A and it will be on the front edge of the bottom of the hood. If you open the hood and look just forward of where the latch piece is, you can't miss it. A quick way to tell without opening the hood is to look at that bridge piece between where the two scoops are on the front of the hood. If it isn't cracked or busted there somehow, it probably isn't original.

The 65-67 hoods didn't have a part number on the hood itself. On the 69/70 Shelbys the part number was the Ford number C9ZB-16612-B, in the same location as the 68s. Hope that helps.
