OK, I need some advice/input here: I rebuilt the 66' center arm today and mocked it back up in the frame. Here's the thing, I suspect that the center arm pivot is bent, specifically out on the end were the relay rod attaches. This wasn't obvious when things were super dirty and the steering box had been removed from the truck before I got it. The issue that has cropped up (assuming the arm is bent) is that the relay rod is contacting the shock as it goes through it's arc of travel. All of these photos were taken parallel to the ground, I had a hell of a time getting the camera to focus correctly. I think the center arm/tie rod mount should also be parallel, not all bent over and in toward the frame.