I would guess depending on how much your clutch responds the limiting factor is going to be wheelie issues. Again depending on the chassis setup, I would try 16/42 (gen-1) and see how that does for 60' and wheelie issues. Plan on trying some other gears. One tooth makes a difference.
I have all the gears 42-48 (gen-2) and depending on the setup end up running 44, 45 and 46. We'll see this year if I can get away with a 47 on motor or not.