Your water pump pulley appears to be the bolt on type. Summit, Jegs, etc: sell spacers that go behind the pulley for a very reasonable price. I belive there are 3 different thicknesses in the package. Used them when I put a Mustang pulley on an old Ford Y-Block to speed up the pump. good luck...

216.158 MPH 12-Port 302 GMC on 70% 171.0 MPH 302 stock head on gasoline 7 years later