Don't want to confuse or mislead you so dug out Beman arrow chart.
What arrow to use at your poundage depends upon your arrow length. You are at the point where you could go either way depending upon this consideration. If your arrow length is between 28.5 and 29.5 then you should try the 400's. If however, your arrow length is between 29.5 and 30.5 you should try 340's. Individual shooting style plays into this as well. Tip weight is really a moot point in my humble opinion.
I would be happy to send you one of each, cut at what ever length you decide upon. PM length and address if interested. Good hunting, Mike