'66 had the windshield hold down hardware that they got rid of later, also vaccuum wipers which had square holes on the inside of the frame for clips (making the windshield frame different). These details they got rid of in the 70s. Also, no backup lights in the tail lights. The backup lights were round, below the tail lights, almost looks as if Ford forgot and added them later. Headlight rings do not have the adjuster holes. The grill light lenses are small, set back in the grille, and are white.