Currently Being ModeratedDec 29, 2012 5:39 AM (in response to PowerPC_Fan)
Nope. You would be very hard pressed to fit the G5 components into the G4 case.
There are a myriad of issues that would need be addressed, but two of the more problematic are the heat sinks and the power supply. One would need to think "out of the box" so to speak....
Beyond that, the G4 case is really poor for air flow, which would exacerbate the PPC processor cooling issues.
Put a G4 into a G5 case. The cooling can be much improved and a quieter G4 can be had.