You're going to need a lot more than a 4-bbl to get this to happen. Naturally aspirated, with no power adders, Mopar has packages that will put an A-body in the 12 second bracket. Among other things, you'll need a 4.10 SG rear, 10" wide slicks, car diet to 2350 lbs, 12.5:1 compression ratio, roll bars, and frame connectors. By the time you get finished, the car will not be streetable.