Shane,

Years ago when these were the only ARF's available we used to find that the plastic fuselage was prone to cracking due to the in-flight and landing stresses. We had good luck filling the fuselage with spray foam that you use around the house. It's light and really stiffened up the fuselage. If you use sleeve type push rods, the control rods are also supported in the foam and internal support is not needed. Try it and leave every thing else stock.

Paul