Another factor that you need to consider is the strength of the hull
at the points where you intend to attach the new chainplates. If the hull
is cored, I would have some serious concerns; even if it is not, I would think that on virtually any boat, substantial reinforcement will nevertheless be in order. Indeed, even if your boat is steel
(as I recall
, some Endurance 35's were built out of that material), you will need to ensure that the chainplates are attached to not only the hull plating, but also some vertical framing; in fact, if the verticles are not attached to the hull itself (often they are attached only to horizontal stringers that are attached to the hull plating), I would fear whether there would be sufficient strength.
Put another way, why are considering moving the chainplates outboard
? Inboard chainplates will provide narrower sheeting angles and improve performance upwind. If the original chainplates have deteriorated to the point that they need replacement, just understand that very few boats have been engineered so as to allow simple through-bolting of new chainplates on the topsides of the hull.