@Red: There's a difference in size, but the alternator's pulley is a different belt width. I figured by using the original pulley, everything should line up better and I don't have to replace the rest of the pulleys on the truck. And I agree completely, it's worth more in one piece, but again, I need the pulley.
@Ken: The generator is in back in one piece and the pulley spins freely. In order to separate the two, and not screw up the innards, I'm wondering how the pulley gets separated from the armature via that big nut on top.
