Almost all my plans show CofG right along or just ahead of the wing spar, with no engine or tank. I never used to pay attention to this stuff. Just built them and flew them. Maybe that explains why some of my builds didn't fly that great compared to others. I will check balance now after installing engine and with dry tank. Thanks.

IMO if the weight distribution correction could be made during building, would be better than having to add weight after. Just doesn't make sense to try and build a model light, then add heavy weights after.