Jeff,
Copy this link, it's as accurate as I've found in guestimating speeds and being CLOSE to a chrono....
http://thearcheryhut.com/calculators.php
Not sure what your "goal" is, but if you are trying to achieve the MAX KE, you're on your way, but you can actually achieve a little more KE with a 450-475 gr arrow, and possibly not have to use the weight adapter.
For what you've proposed, an ACC 3-49 will hit just right spine wise, while weighing in at roughly 515.9grains according to OT2. That should fill the bill pretty well, that 3-71 is REALLY stiff which may not help your tunability much. The 3-49 though will hit right in the middle of the GREEN on the spine selector. If I were setting that up, that's probably what I'd go with. And I get a little better speeds on my calculators (246), but it's usually within 5fps. so it should be CLOSE.