RE: Spine me some arrows!
Running the numbers thru OT, show 400 a little weak and 340 too stiff.
You can get by with 29" with 125gr head with the 340.
Or you can go to 26" shaft with the 400 and 100gr head.
Or just do the smart thing and drop to 65lbs and be good with a 28" arrow and 100gr head.