Well from what I can tell, the 43/4400 motherboards are very similar. They are proprietary and do have the ducted air. But as for the boards they both are the same size but the 4400 runs the DDRam rather than the SDram. The only problem I see is I might have to order the ribbon cable that comes from the front of the case, unless I can get it to fit. They are in different areas and the 4300 ribbon cable I have might be to short. But, I would like to find a 4400 or 4500 board to try.