I realized I needed to have an alignment feature in the rear caps so the projectors couldn't rotate due to vibration. The projectors came with these washers that have three radial "ears" and also have a feature that lines up with a notch in the threaded rear mount built into the projectors. So I turned a recess and milled three grooves that can accept that washer.
After many test fits I roughed up the back surface of the reflector housings and JB welded the delrin caps to them, with them indexed correctly.
This gives you an idea how the washer indexes and locates the projector, and how the rear caps don't allow it to turn.
The final test fit before I seal up the hole for the high beam solenoids. I also mounted up the shrouds.
