RE: reversing and timing an electric motor ?
OK, this is a long answer to your questions. I have the ep with ailerons and I went the brushed motor route first. Used a similar motor to what you are using. There are two screws on the back of the can. YOu loosen these just enough to turn the endbell, there are marks also for reference. Using your wattmeter is a good idea. Before getting started you need to time the motor out of the plane with no prop. much easier, safer.
To reverse this motor to use the gd 600 gearbox, just switch the wires around.
Back to timing. Put the motor in a vise or a test stand, make sure you have the proper rotation, move the endbell just a couple of degrees, you will hear the motor speed up or slow down. When you check the wattmeter, amps will go up as the motor speeds up. What I have heard from others and what I have done myself is to not push it too far. What will happen if you advance the timing too far you will start to get sparking, excessive heat, and more amp draw. Not good. JUst try moving it one mark at a time, you will be able to see and hear it as it speeds up. You should also be able to tell when you have gone too far. Hope this makes sense as I learned this by trial and error, but also picked up a lot by reading about others that have done this successfully. Also, and just as important, break in the motor before you do any thing. Make sure it is in reverse rotation and then run with a couple of D batteries for a half hour or so, checking every now and then to make sure it's not getting hot. This is essential in getting the most out of the motor. It wears the brushes in properly. There is also a water break in method, but I have not had much sucess with that.
Now after all the work there is an upside! You will not know this plane with the new setup. The performance will be surprising and quite fun. Just make sure you watch for the left torque on takeoff as this will be something new as compared to the stock set up. Hope this helps. Jim