Most power hand saws/circular saw will not cut the 3" thick stock in one pass, from one side,,let the lumber yard/mill/wood shop cut it for you
This is why I love both of my worm drive circ. saws. They are the only circ. saw that will have that kind of power to take on such a task.
Jim, if cost is a matter, sanding it and, cutting it square isn't that difficult either. Hint, hand scraper, if you've ever seen any shows of "Wood Works", you'll see David J. Marks use this method.
Or.... if you can find Norm Abrams video called, "workbench". It's completely made of ply and 2by material. If you'd like I could scan a copy of the plans with his material list and email it to you. It could give you some other ideas.
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