I believe the first windshield antenna was used on the Chevelle in 1970. Is there a company that manufactures windshields with the antenna in it for 1964-1967 Chevelles?
Thanks for the help.

I am just guessing here but I highly doubt it. Being that it was never offered in those years the demand for a windshield with antenna would be very low and therefore making it not viable to produce such an item. In addition the years that can accept the windshield antenna have an opening in the cowl for the antenna lead. I don't know if 64-67 have this same opening.