1st Gen Ram Tech'93 & older Rams: This section is for TECHNICAL discussions only, that involve 1993 Rams and older. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
A 600 cfm would be ok and your cheapest route. Might be slightly big...a 570 Street Avenger would be better but they are more expensive. Not really that many smaller carbs unless you find an OEM carb with an appropriate CFM. A friend of mine had a 460 that had a 390cfm carb on it and actually got pretty decent gas mileage.