I currently have a 1973 Dodge Charger with a 318 (auto trans). It, of course has the original 2 bbl carb. I know every thing invovled in switching it over to a 4 bbl and the cost. Will I kill the bottom power (too much fuel, not enough air) or will the top end benifits out way the loss? OR Am I better going with a jetted 2 bbl? Saving the 4 bbl for a dream 440.
The problem would be getting too much air and not enough fuel. You could get a carburetor so big the engine couldn't draw enough air buy the boosters to create the vacuum needed draw fuel out of the bowls. Use a small carburetor, say, 500 cfm and a manifold designed for the 318 (like the Edelbrock Performer 2176) and you should see some power improvements.
iQ52 IS RIGHT, bigger isn't always better when it comes to carbs, a nice 500cfm will work great on the 318.