69 dart vent window adjustment

ahh that makes sense...
I would suggest loosening the pinch block to allow the vent window to pivot.

Next loosen the bolt at the top of the front of the door, Followed by the adjusting nut at the base of the door.

With that done you may get enough slack to rotate the vent frame towards the front.
Once in position cinch the pinch bolt and the top bolt on the front of the door and the one at the foot.

You may need an extra set of hands to hold the frame in position while you lock it in.

If you find that you're not getting the position you want you may need adjust the lower nut on the front of the door.