Rodney-
Look carefully. A 1966 Impala radio has a straight uniform bezel around the dial. On a '66 Chevelle radio, the chrome bezel slightly slopes outwards at the bottom where the pushbuttons are.
Model #'s
1966 Impala AM pushbutton: 986545
1966 Chevelle AM pushbutton: 986528
-Joe
creator of Team Chevelle's radio pages coming soon.