Hi I used the same vent on my 1976
Trillium It fit without any modification to the opening but I did use epoxy to fill any existing holes as they do not line up with the new vent flange holes. Be sure to place the hinge side to the front of your opening. If you place it backwards the wind will catch it if you leave it open by accident while traveling on the roads. I am 6' tall and I have no issues with the crank at all. Good luck ,Duane