Voltage drop at HEI in "crank"

[eric8]

Can someone explain how the voltage drop occurs in the factory pink wire going to the distributor on a 77 C10 originally equipped with an HEI distributor?

I'm getting 12 v in "run" but it drops to 8 or 9 in "crank." All of the wiring is original and hasn't been monkeyed with. It's my understanding on points equipped vehicles, this lower voltage while cranking was normal and done through a ballast resistor.

I thought with HEI trucks this was not supposed to happen. Is this normal?