Surging

+1 What Trailbeast wrote.
Quick rundown:
Surging is lean. Either dirty passages or possibly low fuel level in the bowl.
Sluggish is rich. Try running with the choke on too long and you'll learn what it feels like.
If its more like bucking than revving and dying, then its probably timing. Test by plugging the vacuum advance.

For how an overview of how a carb works, go to www.imperialclub.org look under Literature for the MTSC (Master Technicians Service Conference). There's a couple of pamphlets with the princples of how carbs work. A good intro straight from Chrysler - the real deal.