With a 46xls magnum, I have about an ounce of weight on the motor mount to get the balance where the plane flies nicely. On a low wing airplane you would check the balance with it upside down. I use standard BB servos, and used Dave Brown pushrods to replace the brittle wood rods that came with my Cap. The wire that comes with it was almost impossible to bend into a z so I settle on a 90 with nylon keepers on the servo end. I used Dubro clevises for 2mm wire for extra security- I don't trust Chinese plastic. The .70 fourstroke should give good performance, but don't expect to be able to torque roll...