Stock power steering belt sits out in front of the wp/alternator towards the end of the ps pump shaft. The GM pulley has the belt in towards the pump housing. You just have to switch to the later press on shaft ps pump, mine was off a 77 Aspen. If you are using the stock mopar alternator you can get that pulley from March also.
March crank pulley 10301, Water pump pulley 10312, Stock mopar alternator pulley 214