Weight of the car makes a big difference. Is your car a 2400lb car or a 3200lb car? If it were me and I was using a stock block, I'd go with a 400 stroker. A 440 stroker will get the job done as well, but it seems the 400 block is a little bit stronger. Should be able to buy off the shelf parts to build a BB to get an A body into the 9's (atleast high 9's). You could get a small block there to, but will require more work and maintenance IMO.