Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Not without adding a crontroller card.

No G4 has SATA controllers as stock.

You can install a SATA PCI card from Sonnet or Firmtek in one of the PCI slots. But once you have the card, you can add any size of hard drive you want **Note there are a few specific models of Hitachi and Seagate hard drives that are incompatible with specific controllers, check the literature before buying.**

There are also bridge boards that go on the back of a drive to convert the drive's interface. I think these are a poor idea - there isn't physical room for them in the case, for one thing.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.