Product review (3 stars): Wasn't a drop-in for my 650
I used this for a 650 and found it was not a perfect replacement; the problem appears to not be relevant to other models based on the reviews (but factory replacement part # is the same).  My factory fan was made of black plastic and has a thick hub piece, and I found that the stock motor had a much longer shaft than this replacement. There was no way to use this replacement motor without changes to the fan because there was no way to attach the fan to the motor itself -- the shaft wasn't even long enough to go through the fan hub.  I had to machine down the hub on the fan to make this work.  It looks like it is really intended for use with the metal-fanned units.  Also, none of the screw holes were pre-threaded, although the aluminum is soft enough that it isn't too difficult to do even just using the supplied screws.