I ran into a similar problem when I took the rear brake assembly of to put a softbrake lever on. The 3 bolts would not go back in. I ended up buying a tap and die set and chasing the holes. My theory is that they did not block the holes when coating the frame. How they got the bolts in originally is beyond me. I also put Kuryakyn floorboard spacers on. I had no trouble with those.