with 12V you should either have an ignition resistor [from a FLAPS, one listed for a 58, any model or engine], or an internally resisted coil [easier], which should be available as Echlin #IC21 or Napa #IC14 [I=internal] - check a wiring diagram for 56 up to see how the resistor and bypass are set up here

the ignition resistor cuts the voltage to the coil to increase points life, and bypassing it while starter is engaged insures fatter spark under the starter loading, so easier starting

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics