Unfortunately, without some sort of Tuttle (sorry, not "turtle") adapter (adapts a "A"/"E"
slot fin to a std. depth Tuttle fin box) there is no way you can use an "A"/"E"/"US" slot type fin in your board.
Power box will not fit at all unless you grind/mill off the Powerbox tapers and put a std. Tuttle adapter on it.
You can use either a std. Tuttle or a deep Tuttle fin root in your GO board.
Hope this helps,