I'm running the TFI/HEI setup and wondering what yall have your plugs gapped at? and whats the hottest plug I can get for the AMC V8?

Holley tech swears that my carb is reacting the way it should from the questions they have ask me. They seem to think my spark isn't hot enuff to burn the mixture. The rich idle and stumbling seem to them to be an ignition issue. How could this be?

I'm running Accel 8mm wires and think I have everything on the TFI/HEI setup wired correctly. Help me troubleshoot please

TIA