If you look under the one example of someone installing to a G4 upgraded iMac, you will see two examples of attempts to install to a G4 upgraded B&W that failed. I do not believe it is going to be possible to install to a G4 upgraded B&W or even a Yikes! G4 as we haven't seen anyone doing a successful install to those either. They share a motherboard with the B&W with only a few changes, so it is not likely.