Jimmy, are you building from a kit or just from the plans? I knew an old retired engineer who has since passed and he built a lot of Staggerwings including several Royal/Maratuka kits. He would curse the airfoil on the Royal kit something fierce as being too thin and flying lousy. He scratch built a number of airplanes from their plans and found a 14% increased in airfoil improved the flying and control considerably. He loved the Ziroli design but didn't think much of my little Ace Simple Series Staggerwing. I am planning on building a Royal/Maratuka in the future but I think I'll follow his lead and increase the airfoil thickness just so I can fit retracts better