As I understand it, the one piece gudgeons are from Hobie Europe, and enlarging the holes in the gudgeons is required due to slght differences in distance between holes. There's no baffle or anything keeping the screws from going all the way in. However, when I retrofitted mine, they didn't quite go all the way home either. Never had a problem, and figured I could always drill and tap the transom for the two extra holes in the one piece gudgeon if I felt additional holding was needed. Regardless of the installation, always seal any thhough hull fitting. I prefer 3M Marine 5200 over silicone.