My plane didn't have the dowels, instead there are two bolts and mating blind nuts. Also, there are horiz supports for the bolts thats secured to the wing ribs and the leading edge spar. Since this support was secured only on three sides, it would bend when i tightened the wing down. I had to add a spacer between this support and the lwr surface of the wing. Upload a pic of what you have to get more suggestions.