How many CFM for my 340?

Nice car and with an overdrive trans, cool.

Your car is light weight and 340's love to rev if built right...any carb would work on it..even an 850 holley but I am finding out that the Edelbrock-Carter carbs like stop and go traffic better and think my Holley days are over with (but I'm running two Carter 500's)

The 650 AVS would be a safe pick and get a bit better mpg than the 750 AVS both I feel work work just fine but were you live New Jersey I'm guessing has loads of traffic and police around...you want a nice carb to run around town, not to do WOT high speed runs down the expressways.