[LeeH]

Running rich will cause an engine surge at idle, but your pop sounds like either a lean misfire or a lifter pumping up. Did you restab your dist? The reluctor wheel syncs your injectors and if your #1 plug wire is not in the correct location it will cause injector sequence issues, For example if your a tooth off and have to move the wires on the cap to get enough dist. movement to time the engine.