6 wire ignition switch

[hawkeye]

does anyone know why one 70 charger would have a 6 wire ignition switch and another a 5 wire switch?  also the wiring appears to be heavier in the 6 wire.  the extra wire is brown until the first connection then is orange and runs to the coils and some dash lights.  the same orange wire is there in the 5 wire switch car, but has no wire feeding it from the ignition.  so what feeds the coil and lights?

[nascarxx29]

http://www.ebay.com/itm/16-NOS-Ignition-Switch-2947486-All-70-74-Mopar-Models-Cuda-Challenger-Charger-/350556574510