Forget the dowel, use 4 bolts. Make sure you put some ply on the wing so the bolts don't pull through, use a 1/4 inch play plate in the fuse that sits right against the bottom of the wing, and put a 1/2 inch triangle stock on the bottom of that plate to the fuse side epoxied on for strength. You can use a 1/8th inch ply plate on the back of the wing where you drill through, but on the front you will probably have to go in and put a 1/8 or 1/4 inch plate in for the head of the screw with triangle stock on the ribs to hold it on. Make sure it is good so you don't rip the wing off. Also use the correct numbered bit before you tap the 1/4 inch ply plate so it is the right size and the screw fits right. Use thin CA in the threads and tap a second time after it drys to clean out the threads.