Im installing the electronic ignition from a 75 240 into my 74 140 and I have a couple of questions. I cannot find any info on how this is done using a pre 75 starter without the extra pin to supply 12 volts to the brown wire at the ballast resistor while cranking. That connection is needed in order for the system to work, right?

I also had a question about which coil to use. I had planned to use the coil that is in the car now but I do have an extra coil from an 85 240 I could use. What are the differences between the two? Can one be used without the ballast resistor or does the resistor need to be used either way?

And finally, the switched 12v source. Looking at the diagram for the 75 240 it looks like fuse 3 is used. In the 140 wiring diagram it shows that the blue wire that goes to the coil is from fuse 3 and has 12 volts when the ignition switch is in position 2. Is this an acceptable choice to use?