HEI conversion problem: no spark while cranking

Clip a meter to coil + When cranking, you should see "same as battery" If the battery drops to say, 11.5 on the starter, then the coil+ should be 11.5. In no case should it be below 10 or 10.5

When running, coil+ should ALSO be "same as battery" with the ballast resistor bypassed.

Did you mount the module to a flat piece for heat sink? You must cut the "tit" off the module on the bottom for it to sit down flat. And it MUST be grounded through the mounting screws.

If you are still using the 2 pin dist. connector, "work" it in/ out several times to scrub the terminals, and inspect it for corrosion. There is nothing but a tiny bit of current going through that connector, that is the AC trigger signals generated by the dist. That connector can be trouble.