I replaced all six opening ports with NFM stainless steel opening ports. They have been excellent. I believe the 17″ ports were very close to a drop in fit. The only extra cutting required was for the ‘half-moon’ cutouts required for the two drains in each port and the countersinks on the back side of the outside plate. The exact cabin trunk thickness was not required. The outer plate connects to the body of the window using female threaded ‘slugs’ molded to the plate. You screw the window and outer plate together from the inside. Here is a picture showing how the outer plate sits in a spot where the factory cut the window hole a little too square. (I ended up filling in that gap with thickened epoxy.)
The rest of that folder has a few other other pictures of the install, it should be an open directory.
I used the template from NFM, but it did not line up all the holes perfectly. The moldings from each window differ slightly. If I were doing it again, I would start the drill holes, marking the location of each hole, from the inside using the port itself. I would then use the template to make sure the drill went in at 90 degrees to the surface for each hole. You need to keep each port ‘married’ to each hole until you complete the install, otherwise the drill holes might not line up. These are well built, but they are not tight tolerance parts.
I used polysulfide to seal up the port against the cabin trunk and 4000UV to seal up the outside plate. If doing it again I would just use the factory butyl. Can’t complain though. It’s been six years and they haven’t leaked a drop. 🙂