Classic/Antique Car Repair: VIBRATION, front wheel bearings, universal joints

Question
I HAVE A 1977 CORVETTE, I HAVE A VIBRATION IN THE REAR, I HAVE ADDED A NEW DRIVESHAFT AND ALL 6 UNIVERSAL JOINTS.NEW FRONT WHEEL BEARINGS AND HAD A 4 WHEEL LINEUP. NEW TRAILING ARM BUSHNGS. THE VIBRATION COMES IN A HARD PULL OR SPEED OVER 55 MPH. I HAVE NO REAR WHEEL NOISE. THANKS FOR ANY HELP. CM SIGMON

Answer
Charles;
Hi well if you changed all the  u- joints , than its not that. have you checked the rear mount that is on the rear end above the drive shaft. some times they will go and at hi speeds they start to make the noise and only get worse or they will eat a hole up threw the back deck. for real  check that mount and the rear tranny mount