Ford CMP Coil Bracket

[Lynn Eades]

As nobody else has answered, Yes you need the external resistor with the Ford coil. The Ford coil is in fact a 4.5 volt coil in a 6 volt system, hence the need for the resistor. It might last a while on six volt, but will probably fail.
Tony Smith posted here some time back saying something to the effect that; The Ford coil is unreliable, even NOS ones are the same due to deterioration internally. You are better off with a modern replacement. (this is my recall)

[Keith Webb]

Originally Posted by Lynn Eades

As nobody else has answered, Yes you need the external resistor with the Ford coil. The Ford coil is in fact a 4.5 volt coil in a 6 volt system, hence the need for the resistor. It might last a while on six volt, but will probably fail.
Tony Smith posted here some time back saying something to the effect that; The Ford coil is unreliable, even NOS ones are the same due to deterioration internally. You are better off with a modern replacement. (this is my recall)

You are absolutely correct, the original Ford coils in my experience are unreliable due to age deterioration. I must admit though, the brown bakelite design is very neat.