My buddies 65 dart charger has an 8 3/4 he installed with 355's, four barrel 650, and 4-speed. It was a 273 four barrel from the factory and goes pretty good.:burnout:
Don't forget...factory 273 4bbl's (Commando's and Chargers) had 10.5: 1 compression stock. Your 2 bbl motor is closer to 8.5, so don't overcarb, or over cam it....you'll kill what little bottom end you have now.