After test-fitting the elevators several times, I determined the holes I drilled for the center bearing bolt weren't exactly where they should have been, and it was causing binding. Called Van's Builder Support, and they said I needed to weld the holes shut and re-drill them, then smooth and prime the horns. I bought bettter bushings for the re-drill and contacted Jeremy Tingley Welding in Clarkston to do the patches.