I would not try it on a 1/3 scale cub. I tried to fly one with a US 41 on it and it was marginal to say the least. We put a G-62 on it and it flys GREAT. I would go with the 1/4 scale cub. The balsa USA has a 3 inch longer wing than the sig cub so you may look at it (atleast my old one did. I think the B-usa is 108" and sig is 105")