Completed my mod today, this includes, back-fan replacement, adding a GPU Fan and Modding the case, thought I will post to add some for all my taking
First I replaced the back fan with the XBOX 360 Ultra Quiet Led Fan,
WHISPER FAN STANDARD FAN
DC Power: 12V (at 5v) Original Fan: 12V (at 5v)
Current: 160mA Original Fan: 250mA
Speed: 4100RPM Original Fan: 4600RPM
Air flow: 46CFM Original Fan: 29CFM
Loudness: 38d(a Original Fan: 41d(a
In general I find the case was more silent and air flow seems better.
Second I added a GPU fan, the fan I used was an Akasa 50mm, note that a 60mm does not fit. This brought my overall GPU temp down by 5 degrees and will probably contribute to the CPU cooling as well since it will suck in more air. I wired it into the on board connector, so it will be temp controlled.
Last I cut out that piece of Iron in the back, IMO that blocks the hole by about 30% at least. From observation afterwards I would say my fan now move about 10% more air and is more silent.
Overall the case is more silent now and the air coming out the back is a cooler for sure.
If someone can tell me how to add pics I will happely attach them...