I did it up on TAP with the IBO specs for your bow and it came up at 254. My personal experiences have been that TAP, when using IBO specs, is a little slower than when using actual specs. I think you would be around 260 with it.
How do your arrows fly? That spine seems pretty weak for 70 lbs. and that short bow. Hey, if they fly good, shoot em right!
Good luck with your new bow!