fbodyfreek

i was reading the thread below about vibrations and the drive shaft and it reminded me of mine. but i replaced my driveshaft with an aluminum one that's been balanced. i get my vibration around 80mph and it starts as like a pulse and then becomes just one rough vibration at about 95mph. i too have a poly mount, but it's been doing that since before. i pretty much had this problem ever since i had the car. but it runs like a champ so i guess i forget about it haha. but i was just curious.. any ideas? oh and on a final note, the vibration becomes one solid droning sound when i hit over-drive. thanks guys.