I have been studying the psu differences between the g4 models.

and found this page

www.outofspec.com/frankenmac/wire.shtml

the mobo after sawtooth require a 28v.

in addition
the cpu module requires the added 12v to the 4th leg to quicksilvers

so Alk It appears that i could put a sawtooth mobo into my b&w add the 12 v to the 4th leg to cpu module from quicksilver and it should work.

i agree on the money could be spent as cheap on a complete sawtooth. But whats the fun in that.