my '72 TC is running Pertronix disributor, MSD 6A ignition control, MSD tachometer adapter, MSD coil, MSD wires, NGK Iridium spark plugs, and 12 degrees idle advance. This combination resulted in a immediate starts, smoother idle, a dramatic increase in acceleration off idle, and much better throttle response. I know it doesn't increase peak horsepower but sure feels like it did! Very very happy with this arrangement.