Wade,
Can you stand to look at some more titillating battery pix?
Thought I would offer you some more ideas. This is a DV built Cobra, with some of my own mods. I made a heavier hold-down bracket, and mounted a cut-off switch just in front of the battery. like J, I couldn't find a box that would fit in that cavity, and I didn't like looking at the exposed battery, soooooo I made my own cover out of corregated plastic and felt. I can remove it in about 5 sec., and the whole thing weighs about an once! The battery ground goes to the frame, like J's pic, and I put a braided ground strap on the engine to the frame. I've had no electrical problems at all, and the 10.5:1 460 cranks fine. Use the heavy 2/0 gauge cables, too.
Hope this helps, and good luck!
Dave