Help! Repair suggestions

[LAP123]

I recently bought a 1977 Corvette coupe and when you accelerate there was a loud thumping noise coming from the rear of the car but would go away after I met my speed. I crawled under to check problem and found out that the universal joint coming from the rear wheels to the rear end was striking the fiberglass housing. I replaced the joints but it did not stop the rubbing. Any suggestions on how to fix this problem. I'm a new member and would appreciate any help I can get.
Thanks, Boogie

 

[bill81vette]

Start by checking the suspension components and rubber bushings,around the back end.
sounds like something is weak or is deteriorated.

 

[6880 Mike]

None of the drive line or suspension components under the car should be banging or rubbing on the underbody. Check to ensure the differential is securely mounted.

 

[Vettehead Mikey]

There's no fibreglass near any of the u-joints except the input pinion, so I'm not sure what area you're talking about. Can you post a pic?