HEI Upgrade but No Spark (kinda)

Since you say you get a flash when you release the key, that tells me you have voltage to the coil and module, and you get the flash when releasing the key removes the 12 v.
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You are leaving something out and jumping ahead. OP did not indicate that he "hot wired" the thing unless I missed it, and further, did not indicate he tested the cranking/ bypass circuit. REMEMBER IGN1 "run" goes dead WHEN CRANKING If ign2 is not connected, you will not have spark during cranking