overcarb'ed super six??

I'll make a long story short and get straight to the point. I freshened up a 225(originally 1bbl) with a 2bbl intake, and a 2bbl Street Demon carb. I can get the engine to start with the choke on, but it seems to be too much carb for the 6er. So what are my options guy? One guy at my shop told me to get a bigger cam. That option is still open, but I do NOT want to mess with the head at all(valve springs, ect.). So a really big cam, is out of play. The carb manual said to change the jets in the carb. So what do I do? The Street Demon is a 350cfm. What were the original Carter carbs cfm rating? These are the questions I need answered...