I did it! The fan assy was a bear to get off for sure, but I'm typing this on my new 8 core Mac Pro 1,1... I'm looking for the flashing tool for the EFI on netkas... anyone have a link handy!
The firmware tool to upgrade 1,1 to the 2,1 firmware is here: http://forum.netkas.org/index.php/topic,1094.0.html
You will need to login to the forum to be able to download it (create an account if you don't already have one).