Well well well you have been hiding things from us. What you have is a pointless ignition module in the distributor. It is not the traditional HEI distributor but is like a mallory unit or a standard gm points distributor with a Pertronix ignition installed.
This brings up an interesting idea. Some of these pointless ignitions do not require a resistance wire or a ballast resistor, which might account for the clipping of the wire in your case, and running the power wire from the fuse panel IGN unfused terminal to the coil. There are several of the Pertronix coils which need to run on the full 12 volts from the ignition source and your Mega Fire coil may be one of them.
Here's a good picture of an HEI distributor. See how much bigger around the body is.
