318 Four Barrel Intake

May I follow this thread up with a question? I recently picked up a '72 Duster which had a 318 laying in the engine compartment. It has a 4bbl intake on it, #4100340. My plans are (were) to put it on a new long block that I just picked up - nothing special, just a "regular" 318 long block. My goal is only a nice reliable daily driver, good gas mileage and a little pep. Would I get better mileage with a 2bbl - assuming I kept my foot out of the 4bbl?
Thanks,
C