stockish 340 maybe a 6 pack good or bad ideal??

More carburetors are always better than one.....that is IF the person setting them up and tuning them knows what they're doing. a properly jetted and tuned six pack will STOMP a single four barrel every time. The key is getting them flowed in synch. Once set up right, they are awesome. If you see a six pack get beat by a pretty otherwise equal four barrel, the six pack was not up to its full potential.