Hi Matt,
I will be the first to admit that I know almost nothing about these Stunt Planes when compared to Randy, Dennis, Brett, etc., but I know what the designer of both those planes DROVE into my skull for over a year:
Don't build a USA-1 near 60oz. if you want it to fly as it was designed to fly.That is from Mr. Bill Werwage, himself. He really,
really stressed that the plane needs to be in the mid 50oz.'s to fly correctly. This was all pertaining to the USA-1, and he didn't mention anything about how much power was involved. You can power a brick to fly, but it won't fly like Billy designed his models to fly. He used a fairly thin airfoil, and reduced drag (or whatever) to make it able to fly on his ST 46 and modified 51, even a ST 40 at one point. I don't have access to nitro so I can't do it! He would keep tipping the nitro bottle until he got what he wanted. 20%, and more, was not uncommon according to him. And talking to him was the main reason I got unlimited long distance!
Now I am positive that many will say I don't know enough about any of this to say things, but I didn't say it. I am quoting the *Man*. Mine was 54oz. ready to fly, and regardless of who is flying a model, a 54 oz. USA-1 that is properly set up will fly better than a 60oz. one if all else is equal. Ask Mr. Werwage, I did, often.
Bill Little