Under the battery seems like a good spot but you would have to lengthen four wires quite a bit compared to under the dash option.
If I were you I would hide a chrome box not an orange box.
Actually, I would hide an MSD box and get rid of the "old tech" and ballast resisitor all together, but that's just me.
I disagree.
On a Hemi engine:
MSD shouldn't be a necessity. Only if I was at a very high compression.
Multiple spark discharge is a "spray pattern" of voltage.
Hemi's don't have a quench area as much where MSD may be more needed.
Once the spark is fired; the domino effect of energy transfer has begun.
You can't speed it up anymore than the speed of light.
While you may think that it would create more power, it really won't make much difference.
The spark plug wires are the key to getting the most voltage to the spark plug.
The compression stroke interval is the key to how much voltage is fired.
You could have 1 million volts to the spark plug. But in the end; the compression will create resistance to how much voltage can allowed to pass thru the wires to the spark plug. That ends up making the voltage flow in the wires a limitatating factor. Good wires are the key. I'm running Firecore. Can't get better than that.
Anyway, let's get back to my subject now.