Aileron differential is used to prevent adverse yaw. When the ailerons are deflected, say for a left turn, the right aileron is dropped and the left aileron is raised. The dropped aileron has more drag than the raised one, so sometimes the nose of the plane will yaw to the right. This creates a very ugly turn and also usually raises the nose, which may cause a stall in the turn. Added rudder input in the direction of the turn is also used to prevent adverse yaw.

Aileron differential is NOT used to prevent the nose from dropping in a turn. That's the job of the elevator.

Unless your plane shows this adverse yaw, it's probably good for the ailerons to deflect the same amount. If your SPAD has that much difference in deflection, and all linkages are at 90 degrees to each other, and your radio is set for equal movement each side of center, then you have binding somewhere. That is never good, and should be corrected.

The statement you make "the push aileron" leads me to believe binding may be the cause. Linkages will bind in "push", and seldom bind in "pull".

Dr.1