Great idea Willis. I don't know why I didn't think of that. The kit has one built in. Before the tab I had to put the outboard flap up about an eighth of an inch to get it to fly level. With the adjustable tab I was able to even out the flaps. The tab is up about 3/16". I got in about 15 flights on Wed. It's a great flyer. Here is the setup I wound up with.
Lines 65', 11X5 Zinger wooden prop, Brodak 40 at 9400 RPM.
Sam