Electronic Ignition Conversion HELP

Alright, I got the car running, but it doesn't want to run. The engine backfires intermittently out of the Carb, has a thumping noise (similar to a dead cylinder), the ampmeter reads at +40 while its running, and it doesn't want to idle. The Carb has been rebuilt, it is a Holley Spreadbore. Fuel tank was replaced with a clean one, gas is good. I used a smoker to look for vacuum leaks and there aren't any. I've been chasing this for awhile now. Any ideas?