I got em dialed in as close as my eyes can get em.when I open them the smallest amount using just the throttle plate I see an equal amount of the port holes showing on the top of the venturis.You want to sync the butterflies with 'em closed. The carbs spend most of their lives down in that range. I also suspect the sync is causing (a lot of) your problems. Sync 'em so both just start to open at the same time. See what that does.
If you think about it, if it's popping, the plug is firing. Get the sync sorted, then see where you're at.
They weren't off by a shit load but I guess anything is possible. Gonna run it again tomorrow and see if it makes a difference. If it doesn't, I'll move onto coil swappin'. If that shows a change I'm getting all new coils and wires to prevent any kinda dumb future failures.