Without overclocking it would run it no problem, would be plenty of juice.
It would probably be fine even with overclocking, just saying your PSU will be working quite hard compared with most systems out there. With everything overclocked to the max I imagine you would pull something like 600W under peak load.
EDIT: Most quality PSU's like that Corsair are designed so that if it does pull more than it's rated power for a short period of time, it should cope. Some are even higher wattage PSU's with lower ratings. The Seasonic X-400FL is a good example. I saw a review that said you could pull 600W+ from it no problem but because it's fanless you would need good airflow for the PSU to cope in that case. At 400W it should cope in most systems.