I sent you a small program I made some time ago and that should help you in selecting the correct shaft. My arrows are Beman Hunters 400 @27.25" and shoot a Spitfire broadhead with 4" AAE vanes. My poundage is 62# and I shoot a Cybertec with CC+ cams. That arrow is awsome with my set up.. Also, dont forget I am shooting a release, are you ?
This arrow is shooting 286 fps but I think it will be just under 400 gr. with your extra 3" it should be over 400 for you.

Fletch