Windshield and rear back glass on 67 barracuda fastback installation

I've done this 3 times. You'll need the 68/9 gaskets also. 67 didn't get a stainless reveal molding hugged up against the body so the bodywork at seams didn't need to be even close to perfect. Hold the stainless moldings to your a-pillar posts and sail panels where panel joins are to check their bodywork. The red 67 I have today is the worst of the three 67 notchbacks I have done.
Factory service manual says install the glass from top down. Yes they worked against gravity. We who install the glass from bottom up can't get the top of the gasket to lay to the headliner properly. You dont want to look in the rear view mirror and see the headliner cleats showing.
The pinch weld that the gasket sits on is called a fence. 68/9 owners have had the same problem so its not all about a difference in the 67 fence. There could be a difference in the thickness of the center web in aftermarket gaskets too. Either or, The trick is to trim the fence. Just a sixteenth all the way around makes a huge difference. The glass isn't going to fall out. There isn't a complete fence at the bottom of the windshield. Just a few little segments.
When I test fit the OEM 68 gasket, I had to trim a little more from the bottom corners of the 67 notchback rear fence to get the gasket tight into the corners. Those corners are at the top of a fastback rear glass so I'm not sure how the 68/9 gasket will fit there.