RE: Tiger moth 280motor upgrade
Agreed. One of our club members has a Tiger Moth with a dual IPS drive on it. Performance is better because it can spin a bigger prop, but he also has a LiPoly battery in the plane, equivalent to 7 cells. With the 6-cell pack you have now, you're looking at marginal performance gains and half the flying time.
A higher-voltage battery, 7 or even 8 cells, will give you the best performance boost for the buck. You're not making the most of the power system that's in the airplane now.