Notchback rear glass.

I need to know from the experts!
Is 67 Barracuda rear glass different from 68 -69 glass. A guy is telling me 67 is concave, while 68-69 is convex. Whats the scoop!
I have never noticed this. Thanks in advance. Al
I believe the 67/68 Notchback rear glass is the same. How they are installed is different. '67 uses a wide glass seal with a lockstrip. '68 uses a metal molding with clips installed in the channel. I have a '67, but rear window was installed the same as a '68. The molding is what I need!