I have the Saito .56 in mine with the battery up on the cowl mount ring with no extra weight needed. I had to quit the high speed flat approches as the grass tended to tip it over. So now days I just float it in and try to 3 Pt it.

The Gee Bee is my first and only ARF and I must say it was a nice experiance to build and fly after beefing up the gear mount blocks in the wings.