Hi,
 
In order to make a mod in an old Mac Pro Case (3.1) I need to make a little change on my G3 PSU.
The original Apple PSU fits in a cage and is cooled with a fan on the front of it (pic under).
 
An ATX PSU will not fit in that cage and need to be cooled.
I have to solutions here :
 - cutting the bottom of the plate under the PSU so that the air come from below
 - putting my G3 PSU in the original Apple cage (and removing the EVGA fan)
 

 
I would like to do the less cutting on the cage so the second options looks better for me (and is easier), but I would like to have your opinion on the possible risks, and do you think the PSU will be well cooled ?
 
Thanks in advance