Just find the combo that flies best for you and that bow that is a total weight of 480 +/- gr. Folks can get carried away with FOC weight and end up with arrows that get wonky out past 20 yards. With your draw length, you can probably get a good combo using 400 spine carbons, but you may need so much weight up front for good flight that you lose significant velocity and your arrows drop more than you like out beyond 20 yards. You could also try 500 spine carbons cut to .e.g. 30.5. Are you using a dacron string or a padded 'fast flight' string?