Be careful - that power supply isn't the same as the one for the Performa 630. The 630 doesn't have 3.3 volts, so putting that power supply into a 630 would likely short 5 volts and 3.3 volts together.

When putting a Performa sixtysomethingorother into a Performa 630 case, I had to cut a 5 volt line and put in my own 3.3 volt regulator. Just so you know...