I have a 14' O'day Javelin that I am in the process of redoing the mainsheet system and converting it to a 4:1 system. In this process I adding a new mainsheet block that has a different hole pattern than the original. This attaches to the centerboard trunk and I don't have a way to add a backing plate. I have been considering using 4 #10 self taping screws but I am worried that it won't be able to withstand the forces. The area of the mainsail is 90sqft. I would like to hear what the learned panel has to say.