I have a Super Clown close to finish that will have OS LA 25 power.  I have 2 1/2 ounce and 3 ounce GRW wedge tanks.  Which size would be best for the OS 25. 

     Either will give you enough fuel for a full pattern on a broken-in engine, presuming the usual setup. You probably won't make it through the full pattern on 2 1/2 for the first few runs.

    But I would be a little concerned that they are too wide. How far is it from the peak of the wedge to the "base" (i.e the part that goes up against the fuselage). The wider it is, the further "uphill" it has to suck the fuel.

     Brett

I like your model holder...I assume it's clamped in a vise. Gotta get me one of those built.