Gordon: is this 2nd generation (I am familiar with) or the 3rd and last generation? The wing screws are a strange size. Tam must have some around. MY Viper sat level on the ground and it flew great. I think I used 3421 on the tail, 9411 on the rudder, and regular size for flaps and ailerons(8411 or better). I still have some remains of my Viper and the wing servo hatch is the same so you can look at it and find the hard points. Make sure you double check the stiffness of the stab/stab mounts/rudder areas. I also added some CF cloth to the side of the fuse behind the engine former all the way to the fin area. Get a lot of flap deflection. Glue the winglets...