440 duster. Need engine build advice

I'm assuming you're a grown man? If you want a 600hp street car, build it! My procharged 496 Wedge build is going back into an A-body, and it is what I consider a street car. Even if you just think it will be cool, that's good enough. Don't let people talk you out of what YOU want. Do you homework/research, and a lot of it. Be meticulous and try to think everything through. I suggest not just throwing anything together because that's what you have, or "it" fits your budget.

Have fun! ;)