IF bad..you can jumper around the ballast resister to start it and drive it home
then replace it, the way it works is the resistor is bypassed in start mode to provide a hotter spark from the ignition
then is 'in circuit' with the engine running, so the plugs last longer
when i had my old wedge head 413, i bypassed the ballast resistor
but i had to replace the points more often because they would burn up
plugs were no problem i just when to a heavy duty plug
your 78 440 has a different distribute, mag senor no points, but the same ignition module
buy a spare ignition module and spare voltage regulator module to carry with you
IF you have that plastic body thermo quad carburetor... replace it
