* Drum brakes: These were standard on many models, found on all four wheels.
* Disc brakes: Front disc brakes were an option on many models, often part of a performance package. Rear brakes remained drums even with this option. A full four-wheel disc brake system was *not* a factory option for the 1970 Charger.
So there wasn't one single answer. To know for certain what brakes a *specific* 1970 Dodge Charger had, you'd need to check its original build sheet or documentation.