I may have to investigate that. I have a 7C, so shouldn't be an issue. My solution worked to get the elevators in sync while "up", but now the down elevator has a differential in it's travel. The horns are in the same position on each side. I went way overboard and fashioned a "jig" to ensure the horns were in the same place on each side.

I guess I'll break out the manual and study up on putting the elevator servos on separate channels. Thanks for the input.