The stock crank will laugh at 600whp. It's forged steel right from scooby-doo. There are a few fellas around making 1000+whp on a welded and offset ground crank. An unmolested stock crank should be even stronger. If your at all concerned have it plasma Ion nitrided (salt bath quench will require post treat grinding, Plasma Ion does not) and then stress releved via cryo treating.
If your talking EZ30, Ive heard it almost as strong as the EG. Whereas the Ez36 has little overlap between journals and main webs and has been know to fail.