Make sure the front of the wing seats flush against the forward bulkhead. And then check to see if the hold down bolts go into the blind nuts easily. As gunfighterII said, they will tighten up to the top of the wing correctly at that angle. It actually looks like a very understanding construction detail. That's something you don't often see with Chinese made ARFs. And they might tighten the wing into position in the saddle. GunfighterII's advice is good as is overbored77's. It would be a very good idea to ask this question over in the Aeroworks forum.