My first 2bbl to 4bbl swap.. scratching my head..

It sounds like you want it smooth off the line and a well-behaved daily driver. A 2 barrel carb should be fine for that. Most likely the accelerator pump in the carb is bad. If not, it might be running too lean. Cheapest solution would be a new 2 bbl carb, if you can get one like I did 2 yrs ago for $25, but I lucked out on ebay.

If you go to a 4-bbl intake and carb, you do not want "at least 650 cfm" for how you say you want it to drive. The worst mistake is to "over-carb". It can even lessen your performance, but definitely impair driveability. For best mileage and smooth off the line, look at a small carb or at least one with small primary bores. Say the Holley 4360 Economaster, or a small Spreadbore - Carter Thermo-quad or Quadra-jet (preferably Mopar model).

Finally, get a dual-plane manifold. Even better might be the unique Offenhauser Dual Port 360 manifold, which seems an ideal match for a spread-bore. I see them on ebay occasionally and got one to try on my 383.