Do you have any professional advice that you bolts are lose, or is it just the presence of a hairline crach at the top of the keel? I'll bet you are looking at the typical condition termed the "C&C smile", whicvh most owners simplly clear and refill every year. I'd be more careful about torgueing the bolts without expert opinion than just leaving well-enought alone. if ypou take this discussion to the C&C newsgroup you are likely to get more current and knowledgeable advice about the smile and its correction (or not).
Certified...in several regards...