Sounds easy enough, but I thought it was bad juju to turn the motor at all while the pump was out, heard something about the timing slipping?
Isn't the timing pump what holds the gear in place, or is it supported by the case also?

I think I'll just find TDC, and pull the bad pump, turn the new pump input to match the keyway position, install it, and hope for the best.

 

yeah watch out for the timing gear/pump gear in the front gear case. It will flop around in there but just turn the engine slow without anything impeding the gear and it will stay on the correct tooth, moving as it should.