Restoring a 340 need advice

I would pitch that carb in favor of a new AVS2 with electric choke for trouble free running. Should be about right of the box.

Something along the lines of a Comp XE252 should be a bit more aggressive than the stock cam without being too wild. Maybe a XE268 or some version from Lunati.
Everyone will want to know the gear ratio, tire size and trans/converter details to make more specific recommendation.