66 vs 67 A Body bucket seats.

Head rests became available in 67. It makes sense that the frame would be redesigned to support that option — they wouldn't want to be messing around with two different frames on the production line.. We should probably be more precise, and state that "66 and 67 seat frames are identical EXCEPT for the provision for optional headrests in 67". But most people are really just asking, "Are the foams and covers interchangeable?"