correct application for these headrests

[str12-340]

I got these from a friend who took them off of the bench seat in a well used 71 Dart, but I'm not sure the seats were even original to that car. They have equal length legs. Can anybody tell me for sure what they actually belong in???

 

[Mtrhead]

71

 

[Mtrhead]

I think 1 year only...maybe I'm wrong