This is the part that always get me with threads like this. You want 450 HP or more from a stoke stroke crankshaft, but it's street car, so drivability is a must.
That requires at least 1.32 HP per cubic inch, and while achieving that is possible, it's not going to have street manners. I suppose it's all relative to what you call street manners.
Build a 416" and you only need to make 1.08 HP per cubic inch.