Im running thick gauged wire (cant remember the gauge) from my battery to one single fuse through the firewall then under the carpet then into a small hole in my carpet from under my seat where i have my amp setup. It looks nice there no wires shown unless you push the seat all the way forward. Its not a big deal making a mount for another battery I can always find one in decent shape at the junkyard. Does autozone sell alternators that are much stronger then stock?

 

Im running 2/0 wire........LOL.

The biggest alt from AZ you can get is a 160a

if you want another battery tray then go over the the Dodge diesel forums and find someone with a battery tray for the passengers side. Or if you want I have another drivers side tray and a red top Optima you can use inside the cab.