HELP, Power steering pump problem!!!

[67gmcfleetside]

I recently bought a 70's model 350 long block for my 85 swb. I got a 89 serpentine setup from the junk yard to mount on the front of the motor. I purchased a new power steering pump from advanced auto parts to go on the serpentine. All of the pulleys line up perfectly except the power steering pump pulley. It lines up about half way pressed onto the pump. I tried to get a different pulley, but there was only the one I already had. Is it safe to use the pulley only pressed half way onto the pump or did they accidentally give me the wrong product. Are there different offset pulleys out there. Any advice would be much appreciated...

Thanks