Thanks TacomaAustin.
Are you recommending removing the existing BlueSea ACR and replacing with a DC DC charger? This almost doubles the cost of the upgrade.
Two options that I'm considering, both Victron - one is isolated and one is non-isolated, I don't run sensitive electronics from the camper battery while driving so it looks like a non-isolated charger would be OK. Any thoughts on this?
I like that Anderson protective cover but I'm still left with the issue of protecting the cables where they route through the hole in the sidebed.
I'm not sure if it matters but I'm also upgrading to a SOK 208Ah lithium battery with a Victron MPPT controller (Victron Energy SmartSolar MPPT 100V 30 amp 12/24-Volt Solar Charge Controller (Bluetooth)) that will replace the existing Zamp PWM controller.
non-isolated is good enough. The isolated ones are designed for marine applications.... nothing like having a BIG voltage difference between the dock and the boat and thus between ones legs.... 
I used to use a plastic grommet in a 3/4" hole to protect the wires. Now I use firewall pass through connectors from Summit Racing - Summit Racing SUM-G1431-RED Summit Racing™ Bulkhead Cable Connectors | Summit Racing
Yes, TacomaAustin is recommending that your ditch the ACR and go DCDC. I think you might find that without the DCDC, your 200+ AH LiFePo4 batteries will suck down more than 50A and trip your breakers. I'm using 2AWG wire and 100A breakers, because I also occasionally want to direct connect (I have a switch for that) both sets of batteries, like when I am boosting the truck from the camper, and/or trickle charging the truck from the camper.
As for the MPPT... Thanks for listing that item. I was confused about the 12/24 part of your description and had to look it up. I'm using the same MPPT and had no idea it was self selecting the battery voltage. Cool.
Also, when running your wires, are you running a pair, or just the one and using the frame as the ground return? I strongly recommend not using the frame.
