Improving acceleration using 2bbl Carburetor?

To answer the OP's initial question - no, a 2bbl carb will not improve initial acceleration. It will breath better to give maintain torque at higher rpm, thus more max power. If anything, it will give poorer performance at low rpm, like when starting from a stop. Good that you have the BBS. My 1964 has the same, and for those that don't know it is rod-operated (no cable). My 1969 slant had a Holley 1920 and it was terrible, going thru ~4 over 18 years before I finally got a rebuilt one which ran perfect. I had been thinking valves, intake leaks, and such, plus no mechanic could find why it ran poorly and stumbled around idle. The Carter BBS is similar to the more common BBD. I don't know if many parts interchange, but the knowledge does and you can find posts how to tune and rebuild it. I think its direct descenant is the popular Edelbrock 4 bbl used on maybe 90% of small-block Chevy's you see at car shows.