If you define it as after the gearbox you are correct (otherwise the aircraft would roll).
Propeller torque is measured after the gearbox. So measuring 'engine torque after the gearbox' is propeller torque! Both would be measured in the same place so they would obviously be the same.
I think some of the confusion is related to the ambiguous term, "torque". Torque is defined as the tendency of a force to rotate an object about an axis, fulcrum, or pivot. That means ANY force and there are lots of forces in play when an airplane is in flight. As I mentioned above, propeller drag constitutes a torque and is sometimes understood as propeller torque, mostly to people who have only flown direct drive propeller engines. I think tcyandy needs to clarify exactly what he is asking so that he can get a clear answer.