You're right, I think my max is around 70A at 120 volt. I guess I was presuming you feed a subpanel with 240V so that it provides a balanced load to both bus bars. So you're saying I could feed the panel with a
60A 240V breaker using 6/3 romex, and then pull more than 60A at 120V (e.g. install 7 20A 120V circuits with a max simultaneous draw around 70A)?That would make this all easier.