[JAR0023]

Couple of good threads on this if you search. As already mentioned you need to match the glass to the seal. 911/964/993. The flat pinchweld flange that runs along the interior of the window opening is larger on the 964 and larger still on the 933. So if you install 964 glass and seal on an earlier 911 it works but the flange doesn't completely fill it's slot on the seal.

J