where to find technical diagram of G5 motherboard standoffs ?

does anyone have or know where i can find a technical diagram detailing the positions of Powermac G5's motherboard stand-offs(where u mount the m/b)?

any help is appreciated.

thanks

another thing is, i am torn over my route of advancement to mod the G5 casing.

1. Do a inverted ATX and mount the m/b over an aluminium plate
2. Rotate the front and back such that the mounting is a 'normal atx'

both entails serious modding, drilling etc.