Rob - I've got some photos posted on the smbforum that show pretty well how the battery frame will sit - the battery bottoms will be less than 1/2" below the bottom of the frame rail, but part of my mount will sit about 2" below.
If you use these boxes, I guess you'll just have to make plans to add some rock rails that hang down the same, right?
That works out perfect that you've got 3.55's - anything lower and you'd suffer I would think. The nice thing about the 460 grunt is being able to make up for the shortcomings of the C6 gear spread, no doubt.