Vibration???

check your u-joints & also check for play in the transmission tailhouse bushing where the driveshaft goes in,usually if the bushing is going bad it will leak a little fluid by the rear seal. last week mine started a vibration that came in at around 80mph & I found my tailhouse bushing has gone bad. 80mph w/3.90 rear gears = apprx 110mph w/stock gears:nono: my trans is a stock T-5, not designed to be behind a 393 stroker with me driving. Good luck