Stock crank will hold it, Mibrum hasn't twisted a crank since he fixed the fuel wash problems, and he's well over 1000.
Go to
http://7Mpower.com and have a look at the writeup there by Will Neely.
You will absolutely need new flywheel bolts, Duane snapped his at ~800. You'll need a better harmonic balancer on the front, too, talk to ATI about getting one custom made.
I suspect you'll need new bolts on the driveshaft to rear diff interface, too.
There's a crapload of other stuff you'll end up needing - as suggested earlier, have a look at some of the already existing high horsepower builds, that will give you an idea of where to start. Remember you're shooting for even higher numbers, so everything will have to be one step up.
Oh, and one last thing - be prepared for a lot of stuff to break.