6.4 hemi charging system?

This site talks about automotive (NOT house wiring) ampacity for TWO PER CENT VOLTAGE DROP. If you are going to talk about wire capacity, you MUST consider and specify how much drop you are willing to accept

https://jascoautomotive.com/automotive-wire-amperage-capacity-chart/
2% of 14V is about .3V (.28)

You also must know the LENGTH and you must know if that length figure is taking in the GROUND SIDE, such as in a wood boat, where there is no frame or body ground.

This chart here, EG, shows that no 8 ga at 12.4ft wire length, and at maximum of 2% drop is ONLY GOOD for 30A
https://wiringproducts.com/pages/wire-amperage-capacity-chart