Greetings,
Well, you would think since the XBOX is PPC based there would be tools in the OS X world. Uh, you may be able to install the "correct" model drive and have it recognized by the console. The reason for the tools is that you need to move the signature files off the old drive to the new, and format the drive in a manner that the 360 "likes."
The reason for the specific drive is due to the 360's on board BIOS not recognizing most hard drive cylinder/head/sector layouts.
Find a windows box or a friend with one. . .
Hope this helps.