Well I found what was making the vibration while driving. One of the U-Joints on the rear drive shaft had no needle bearings left in one of the 4 caps. I replaced that one but I might just go ahead and replace the other one as well. I think I am going to re do the first one since I need to replace the yoke straps and bolts, may as well since it is all going to be apart anyhow. I also need to replace my power steering pump pretty soon because it is starting to squeal with the lovely sound of failing bearings. Granted this all seems like a ton of repairs if you look at what all I have done since I got Spero but it is not too bad. She does have 217000 miles on her at this point so in the grand scheme of things that is a fairly small list of repairs.