RE: Hangar 9 20cc Tiger Moth
One thing I see off the bat. If you use the Hangar 9 aluminum mounts, they are around 4 ounces heavier than the nylon ones. Also, that is more forward than your lead so you may get to remove 5-6 ounces of lead by using the aluminum mounts for your Evolution 26.
Also, I can't tell from your picture but can you put the Ignition and Rx batteries both on the motor box instead of lead?