Man I used the short ones on my ailerons! I hope I don't have any issues. I'm using 1.5" arms on the ailerons and 1.75" in the elevators.Pretty straight forward build if you have the elevator pushrods after market ready, and use the elevator pushrods for the ailerons. I always start with the hinging and horns. Be careful, there are a set of horns in another bag that you need. Don't use the short ones.