I bought a used third member with 3.55 gears years ago and when I installed them they howl. I put up with it for a long time. Then about 5 years ago I bought a new OEM 3.55 ring and pinion from Mancini's. I had a one man shop that does only rear ends, set them up with all new bearings. When I installed them they also howl like the last set just at a different rpm range. The guy told me that the gear pattern looked great when he set them up. I have had people tell me the howl might be coming from the axle bearings, but I don't believe that.