The spacer must go in front of the pulley, between the pulley and the fan. If the pulley groove don't line up with the harmonic balancer, a spacer will do you no good; you'll have to press or "unpress" the mounting sleeve on the pump shaft. If the back edge of your fan hits the harmonic balancer after you align the pulley grooves call Patrick and he'll send you another spacer for free. I did all of this stuff myself just last week.
