minnesota crash,

Recommended for the Surpass .70 is:
Sport & Stunt models: 11x8,11x9,12x7,12x8,12.5x6
Scale models: 13.8x8,14x7,15x6,16x6

For slower flight, I'd use a larger fan/lower pitch. Better spool-up, torque, and climb-out . SIG recommends a .40 to .46 engine on the Kadet senior, so check that CG!! The surpass is going to be heavier, and reinforce the firewall, as the bigger engine has more pulling power on the plane. And, as in my above post, check your ground clearance. If you take off / land in the grass, little ground clearance is going to stall the engine, and if you land on pavement, even a small bounce could cause a prop strike, and do some serious damage.

Maybe CaffenMan can weigh in on this one........