I suggest you try what I've been doing before going to all the effort/expense to add straps. If you have the arrangement with two 3/8" studs coming up from the hull and they're in good shape do the following. Clean the threads up thoroughly and do the same for the nuts (or just buy new SS nylock nuts). Install a beam casting with boss at the outer position and a smooth without boss beam casting at the inner position on all four corners of the boat. Apply plenty of anti-seize compound to the threads before assembly and tighten carefully and a little at the time, DO NOT overtighten. You will occasionally have to check and possibly retighten the nuts. I check mine whenever I start hearing my boat creak and/or after a good thrashing. My boat seems OK this way without the straps.
This is the best anti-seize compound I've ever found. It is highly effective, but very messy.