I just bought a bigger fan for my new XBox. Do I want the air to flow in or out?

One more question for you guys, Are the bios chips inner changable between different version XBox motherboards?

I am new to this XBox stuff.

The reason I ask is I was wanting to attemp to put this Chameleon chip back in the new XBox, but if I goof it up, I was wondering if I can use the original bios chip instead of flashing the new one. I fear if it doesnt work, I wont be able to put it back in working order, if I flash the new one.
If this is possible, I would not have to flash anything cause the old one is already flashed for the chip.

For the fan I have mine blowing out.


Tyler!