Nacho is wrong folks.

You can’t compare 66-67 to 68-70 mirror positions because they go in different places.

In 66-67 you look through the wing window at the mirrors on both sides. I have a car that came with them factory.
In 68-70 they are behind the wing window and you look through the door glass at the mirrors on both sides. The driver can’t see down the passenger side of the car in a 1970 b-body pass door mirror. I have 2 cars that came with them.