Battery cables
On my 66 Dart with power steering, no ac, the original negative cable mounted to a bolt under the left motor mount. When it broke the previous owner's mechanic mounted it to the motor mount because the only way to get at the correct bolt is to pull the motor mount off and change the cable, which is kind of a pain. The battery end went through an adjustable plastic strap that is clipped to the radiator support next to the battery, and then the cable went over to the battery. As for the positive cable, it originally went from the starter up to a square sheet metal type bracket that is mounted to the outer rear top intake manifold bolt near the base of the carb and then it goes over to the inner fender where there was another plastic adjustable strap clipped to the inner fender in front of the electric windshield washer pump, and then it runs to the battery. There isn't any smaller cables/wires coming off of either of the larger cables. My 65 Dart GT, and 65 Dart 270 both /6's, were set up the same way.
To get a correct measurement for the new cables, run a piece of string along the route you wish to use and leave a few extra inches at the end for cable slack, measure the string and this will be the length of the cable that you will need to buy. When I redo mine I will be making my own cables because there really isn't much to it.
Hope this helps,
Paul