Second question of the day. On this page Steps 9 and 10 of the instructions say to dimple the rivet holes and use AN426 (flat head) rivets. If I do that, the nutplates stand off a bit from the surface of the rib due to the protrusion of the back side of the dimples. Or do they mean to dimple the nutplate mounting holes as well? I'm too cautious to set those rivets until I find out.