Drive train vibration. Scratching my head.

Follow up. I did 3 things. I removed the 2 hose clamps I was using on the driveshaft to determine out of balance. Remember the vibration was there prior to placement. Secondly I swapped out my trans mount with a used spare I had per RRR however I do recall doing this months ago. Lastly I noticed that the driveshaft had a 4 inch clean section djrectly above the H pipe band clamp with bolts facing up. Spun it around. Anyway the vibration only comes in around 75mph now and is mild. I will undo one thing at a time to determine which was adding to it. Doubtful it was the clamp because no damage on bolts or shaft. Maybe a nick but would have had scraping noise.