If you want a stockish look go with 440 Source Stealth heads (Edelbrock knock offs that look stock). An Edelbrock RPM intake (fairly stock looking), headers (any that fit well) and a decent cam (Hughes Engines sells Mopar specific shelf cams), u could make 400 HP easily, probably well north of that. I think the biggest hurdle is finding Pistons with a decent compression height. This is overkill but there is stroker kit for a 383 (440 Source sells one along with other vendors) that uses a 4.25" arm, 6.535" rods and a 1.32" compression height piston that is easy to get to a zero deck for a quench build. It ends up being 496", definitely overkill for 400 HP, but an easy recipe for 500+ and have a stock look.