I changed the tank to a sullivan 16 ounce. I enlarged the area for the tank in the former, added a few braces to stiffen what i ground out, then added a small floor for the tank to sit on. I needed to lower my tank as much as possible since I am running a OS 160 twin 4 stroke. The carburetor is on the bottom so I need the tank lower. The thing I really didn't like is how loose the fit of the stab is in the stab cut out. It allows for a huge amount of variation in incidence. I set mine in the middle, and now find out that I am a degree off from what is called for. They didn't publish the incidences when I built mine. I found out now the wing should be +2, the stab -2 and the motor -4. I personally think that these number are quite wrong for this plane. It is real pain in the ***** to land!