Purchasing ignition parts..

So, I am having some issues when purchasing ignition parts for my Challenger..
It's a 73 with a 340 and factory Ralley package.

Go to buy a ballast resistor and all the parts stores say it takes a 2 post..
I have a four..

Go to get an ignition module, they say here is a 4 post unit...
I have a 5 post...

The car is pretty original and doesn't seem to have been changed or converted..doesn't seem to have been anyway...
I checked for 72-74 same deal regardless of engine...

Anyone else have this issue? If so whats the deal?

Hope everyone's holidays

Jer