It is a brand new 8.8 w/373's from frpp. Figures I bought a reject so anyway I went and spend another 400 bucks to have a shop diagnose the knock i was getting from going in and out of throttle. He said the play was coming from the spider gears. At fist he thought it was the pinion or something. He put new spider gears which fixed it about 80 percent but the knock is still there slightly which he had told me. The axles which are the ones from the old unit still seem to have play in them. It never did this with the old unit. I guess im supposed to just deal with this? I know some will say "take it to another shop". The truth is I know the guy pretty well and he has done many gears on stangs. Any suggestions?