3.9 v8 serp lower crank pulley wobble

I have a wobble on the crank pulley . I have put it on as tight as I can using an air gun but still wobbles so I went out and purchase a second hand one and that wobbles too . Any ideas . Could it have anything to do with the woodruff key located on the crank. ??? When I put it on there is a bit of movment left to right before I put the nut in . Thanks

sounds wrong..mine was tight as tight thing..wrong pulley??