I have been running my Charger this way for about 2 years since completing the restoration without any issue. I have excellent cranking power with the battery relocated and everything seems to work fine except it doesn't kill the engine when the master shutoff is turned off.

I enclosed my current wiring setup of the battery. I used 0 or 1 gauge wires for the battery to the starter and the grounds. I got a huge fuse/link to protect the car should something happen to the wire.

I thought I could kill the car by shutting the alternator field wires so I tapped into them and ran wires back to the 4 lug shutoff switch.

I added the pic of my altimeter since I am running the bypass upgrade outlined by Nacho in past posts. I don't know if this makes a difference in my issues.

I know the popular thing is to run the Ford solenoid but I would like to avoid that since I have all the wires in place and would rather not re do everything and I was able to make this work on this car several years ago without the ford solenoid and only a 2 post switch so something must be possible LOL