Quad Mag has fixed timing at 24 degrees and I believe it is now ROAR legal as well. If you need to have adjustable timing, you can trim the stop tab.
I have this motor and I am highly impressed with it in my TC3. The speed on this thing is unbelievable and I was easily undergeared, probably could have gone up another 2 teeth ( 48 pitch pinions ).
This motor has loads of torque and crazy top end. If you get it, run it as it is out of the box and see how you like it. Begin your gearing as you would gear a stock motor. This seems to be the best way to get it tuned to the track. You probably will go up 2 teeth, maybe 3.
If you want higher power output, look into 767 brushes. these work great as well, the 766s just wear better.