Clunking noise from the rear end???

[Chris_32212]

August 20th. I drove her down to PIR and everything was fine. Got to the burnout box for the first time and started to heat up my Summitomo HTRZ rear tires and I felt the rear end make the usual drift to the right because I don't have C4 beam plates yet. But during the burnout, I felt something break. The car snapped sideways about six inches further to the right and stopped as if the body of the car hit something (which of course it didn't).
I made my pass very gingerly and got back to the parking lot and jacked the car on both sides and could not feel any play in any drive shaft or half shaft. Could not feel any play in any of the suspension components. Yanked on both wheels in all directions with the car in the air and could not feel anything out of the ordinary. I decided to drive the car home where I could take a closer look but slowly got it up to free way speed without anymore noise or other issues. I have a spare six speed corvette parts car at home so I got on the throttle harder and harder but everything seemed fine. Go ahead and feel free to cringe but I took the car back and raced it more than ten more passes at PIR. I felt and heard a "clunk" several more times from the rear of the car throughout the night but it never broke. I ran 12.6 @ 114mph multiple times and drove it home. Turned into the driveway which was a tight, slow, right hand corner and heard it clunk three or four times. Clearly there is something that needs repair but I had to head out to Eastern Oregon to help my parents out and heven't had a chance to look at it since. Any ideas? On the way home, I went over several speed bumps with no nothing noticably wrong with the supsension. I would think that anything in the drivetrain that would be causing the car to make that much noise from the rear would have broke with the amount of extra abuse that I put on it. So the only things I can think of that might be causing it would be a wheel bearing or something. It shimmies a little while turning but still goes in a straight line pretty good. Penny for your thoughts???