These are the 3 wires you need to replace.
* Alternator positive to battery positive with or without optional fuse
* Battery negative to chassis
* Chassis to engine block
Ideally anything above stock wire size is an improvement... but remember bigger is better. I highly recommend 1/0 gauge wire... or at least a 4 gauge wire.. AH yes and your setup is like mine... Your alternator wire runs from the positive battery terminal to the "mega fuse". From the "mega fuse" to the alternator. Mega fuse is located on the fuse box, probably hidden/protected by a piece of plastic.