I got a rear glass from a 72 Dart donor and attempted to install it into my 67 Dart.

It basically falls through the opening. It appears to be at least 1/2" too short.

I had purchased the butyl tape sealant and was ready to go but discovered this when I dry fit the glass. I guess I should have done that before I purchased the sealant. At least I had not laid down the butyl yet. It appears the glass was installed with butyl tape in the donor. I spent an hour cleaning sealant off the outer 1/2" of the glass mostly on the inside.

Are 67 and 72 Dart rear glass openings different sizes or am I missing something? Would it work if I used a gasket instead of buytl?