The only difference between the side glass from 67-69 Barracuda’s is in the stop that is used to limit how far up the window winds up. In 69 there is a hole in the bottom of the glass that controls this. There is a plastic knob that attaches into that hole and contacts and adjuster that’s in the door itself. Earlier models did not have this hole. They used an adjustable bracket attached to the door that limited the window mechanism from going up too far. I changed the glass in my 69 Notchback years ago to the earlier style but I had to use the earlier bracket arrangement so I know that you can use earlier glass in a later model but I’m not sure if it’s as easy to go the other way. Perhaps a member can post pictures of a 69 door with the door panel removed and I can mark it up to show you what I mean.
