Yes, it appears so, check out this link.

http://www.welovemacs.com/6612904.html

You can set this one at 600 or 650. Maybe it is the same as the stock G5 power suppply. I am not too sure. Souds like a good mod. Are you planning on submitting for the contest?

Cheers.
_________________________
"Fix it 'til it Breaks."

Jacob - EiC & Director of Technology
Mac Pro Quad 2.66 - 4GB RAM
160 GB SATA RAID 1 - 650 GB Storage
Quad 19" Widescreen LCDs
Accessorized to the Hilt