Ya hear that kids? Just say no. Don't do drugs. Supertiga had to learn the hard way. Supertiga, glad to hear that you are recovering from Chemo. Nice work on the engine and wing wires too! My Saito 180 weighs about 32oz and balances just right, so I'd recommend an engine that weighs at least that much unless you are up for modding your GB to lighten up the tail section. The latest 20-30 cc gassers should work nicely in the GP GB if you are concerned about fuel economy. The high wing loading just takes getting used and that is not an insurmountable task. I find my 12 pound GB to be easier to manage in 10+ mph winds than my 8 pound H9 Corsair and they have about the same wing area. Just shoot for the first flights with the wind parallel with the runway for best results.