Yea, if it seems fuel starved, even with the E clip at the bottom groove of the needle, you have an air leak. Most likey where the manifold goes into the carb, or manifold to engine. Very common.
Alternately, you might need to drill a hole in your gascap because it isent venting properly. Smallest drill you can find, theres allready a 'dent' along the rim you can drill into, but you gotta drill into that and into the next chunk of metal behind that, to vent it.