Regarding the TT GP-07, I'm putting it in a 1959 Berkeley Impulse RC build. Plane has 46" wingspan with about 295 sq. in. wing area. Nose cheeks came in too narrow for the Enya 09-III TV, which is my preferred engine. With a 7x6 wood prop, it definitely would not be considered underpowered. I'll know more when I actually try to fly it.