CARSII - there's a bit of a list that people here have developed for reinforcing the 70" Revolver - you might want to keep reading these pages for details. My quick list - replace main and rear gears with Dubro's, reinforce the floor for both gear, use Robart Hinges, add cornering to renforce outside corners of the engine box, use 4-40 pushrods and hardware, some install twin elevator servos in the tail, re-epoxy in the main wing engine boxes (they sometimes pull out in flight). I'm sure there are other's I'm forgetting.