Help Junkyard coil for HEI distributor?

Here are a few pointers.
When you say you grounded coil, I assume you bolted down the aluminum mount. While that is good, it is insulated and has no effect on coil operation.

Without current limit the coil can be damaged! The ignition module has that, it limits the current to about 5A. It also limits the current by controlling the time it pulls the negative lead low to energize the coil. When the negative lead is released by module, the spark happens. The damage danger: it only takes about 3ms to charge the coil fully. In the long term the only current limit in coil is the resistance, that is about 0.5 Ohms. At 12V, the current would be 24A, in a fraction of a second. Since human reaction is typically 50ms, that is 0.05 seconds. So if you want to test, be quick, and touching the negative lead can be a shocking experience.

If both +, - leads of coil have 12V, that means there is zero volts across the coil, when you ground the - lead, the coil is energized. The time it takes for you to measure, the voltage is enough to burn a coil. So, are you sure you have a good ground for your test, and plug grounded?

Others may be able to help with module pin connections.