Well, before you start drilling holes, check the condition of the hinges, especially the pivot pins. I had the same problem, no matter how much I adjusted, it was still up at the rear, and higher on one side. Turned out the pins were worn on the left side, not letting the hood settle down all the way. new pair of hinges, and now the hood shuts al the way. Seems to be a common issue with the '55-'59 and '60-'66 trucks.
