I think going high 12s with the parts you have will be tough to do. I could be wrong, but I bet the TCI breakaway is similar to the factory hi stall. 383s need some converter. This would be much easier with a 440 but I realize you already have the parts. Big stall ,big gear and big cam in the engine you have might reach your goal but will take away some of the streetability. Depends on what you can live with. As Moparpollack suggested, you could put a kit on it.