Power Steering Pump Question(s)

[Jordan]

Other than the hub (and pulley), is there any difference between the pump with the conical hub and the one with the straight hub?  Are they interchangeable if you have the correct pulley for the pump.  That is, can I swap a pump and pulley with a straight hub with a pump and pulley with a conical hub?  Is the mounting the same?  Appreciate any insight on this.  Thanks.