Originally Posted by 62_Galaxie_500

Now that I think about it, the '58 and '59 don't look anything alike. The '63 and '64 don't really either. D'oh!

I stand by the other groupings though:
housings
1961-62 - Same fenders, hood, roofline, doors.

Tail fins and I don't think any of the parts interchange- they were stand alone models
1965-67 - Lots of differences, but the average Joe will mostly notice the similar headlights and sharper body lines that these models share.

65 had sharp square lines, 67 was rounded and 66 was a combination of both. Nothing interchanged.