Great forum towards finding concourse information. I have begun the restoration of my 72 Mach 1. I have had this car since I was 15 and 27 years later I am preparing to do a full concourse driven restoration. I have the original build sheet (very legible) and Eminger invoice on the car and I am trying to decipher the build sheet markings. I understand the tag identifiers and Bob Perkins assisted with some of the color codes. What I am trying to find out is the "N" under the hood column. My car has the NACA hood that is original. I am trying to understand if it should have had ram air or not, or the black out treatment on the hood. Ram air is not indicated on the invoice, but I did not know if it would be. I will see if I can attach documents to my post of the build sheet and invoice. Maybe other could help or possibly direct me to a source.