I am a first time owner of a corvette and aquired a 1987 in great condition with 204K miles. When I depress the accelerator at any speed, the rear end seems to "shift" left. When I let off the accelerator at any speed it seems to "settle" to the right. It feels like only the rear end no front end movement is felt. It also is only a slight movement. I don't know if it is due to torque or something loose in the rear end (handling and cornering are unaffected.) Has anyone experienced this before?