I agree on that balance point I have always found that with high wing trainers you need to put your finger tips under the wing at about 1/3 of the way back from the leading edge (front of wing) , the nose should drop slightly(hell it can swing way forward and still ok) if you have this fly that sucker!
Remember nose heavy is ok to fly, tail heavy you better have some experience.
I once put a supertigre .51 in an avistar .40 I didnt add a drop of weight to balance it, it flew great always on the verge of ripping the wings off , although when i would run out of fuel it would drop like a rock, just head for the runway.
Good Luck Dude