Earlier threads suggest '67s used 8" mirrors. In 1968 there were several NTSB ordered changes to cars, including mirror changes: "Jan. 1, 1968: Sideview mirror on driver's side must provide a clear and reasonably unobstructed view. Passenger-side mirror required when rearview mirror cannot provide good enough views because of the size and placement of the rear window." (Chicago Tribune article April 21, 2002)
So, did the wider rearview mirror meet the required "unobstructed view" without GM adding the right outside mirror?? I don't recall anything that indicates when the wider rearview was started. During the '67 model production, beginning '68 production, or during '68 when the left mirror changed?