Strange I wonder why your CG balanced different then mine... I used hitec 425 ball bearing servos and the same REC with the batteries under the tank up front with an OS FX 46 and it’s CG was 5 inches for mine...

I flew it that way and it would fly, but was way tail heavy and performed as such....

I am really not that happy with the 80 either as it want to torque roll now if I don’t handle the throttle right… Of course once it is up to speed it fly great and fast…