Are you speaking of the axis down the center of the servo post? I'm certainly no engineer, but it seems the point you'd want to be certain of are the points on the servo wheel where the push rod connects. These points should be at the same height in relation to each other. While not measuring them, they are very close on this model. I have also measured down from the elevator control horn and each nylon connector is now the same distance again, after my earlier experiments.

I also changed the servos to S3010's. They're still standard servos, just high torque. This improved the synchronization, but it's still off. Moving to S3151 digitals could improve still more. But it seems at this point that the absolute answer is the MSA-10 servo synchronizer. It will allow for center, and full travel adjustments for the individual servo, since this capability is missing in the 7CAP radio. The cost is roughly the same for two S3151's as for the MSA-10. I'll just need to pick up a couple 12" extensions, but that's true in either case. Does anyone have experience with this synchronizer?