Well I kind of need some specifics to guestimate what speeds you will be getting, but you won't need that overdraw. Sounds like you'll need new arrows because even though today's risers will allow an arrow shorter than the draw length, you're arrows may end up being too short. In fact, I would highly recommend ditching the overdraw, just because you can get arrows the same weight in a longer length, and the longer arrow will stabilize better.