I have no recent experience with gas motors, my last one was a Quadra 50 back in the '80s. However, over on RC Groups, there is a thread stating the Staggerwing does fly with the G-26, so... Maybe someone with more experience on them will jump in here.

The Staggerwing is a great flyer, but it needs speed, especially on take-off, so the motor needs to have excess power. I do not recommend marginal, or bottom of recommended size. You will NOT be saving money. Parts are no longer available for this model, and it always comes out heavy.