[bobH]

Can't tell which 9-inch you refer to. In addition to the above posts, and from experience, I can add that if the 9-inch came from a 57-58 Wagon or Ranchero, then there is an option of re-drilling and installing studs for the 5-on 5.5. Eric Vaughn (the wheel guy) used to do this, and made this mod for me, several years ago. At the time, he said that these 57-58 rears were the only ones he knew of that had a large enough axle flange, to do this. (I'm posting ancient history, maybe a dozen years old, and I'll bet there is new info available today. Back when, it was the 57-58 version that was chosen because it has the correct width to look right under a 34.)