The one's on the 73+ cars stay open just fine. I think you need to swap the whole window as a unit though, I don't believe you can just switch the latches. Plus you have to notch the earlier metal sail panels to clear the 73+ mechanisms.
Correct on swap as complete unit. Latch and glass mounting points are different so no swapping the latch or glass alone.
The 73 up latches can "over extend" and begin to fold closed backwards just a bit which locks them in position. The wind can not close them.
I notched the 70-72 metal panels to accept the 73 up windows.
Very simple to do and looks good. Nibble away at it though, dont just cut out a chunk!
