This is an issue with my '71 with an '83 L28 and '83 5 spd installed. I had a combination of issues happen while on the track at Road America. First, I think the fuel regulator started to go bad. I lost power and died. Had to get flat towed in. While diagnosing the no fuel problem, I got the car running again. Then when I was revving the engine, I started to get a real severe vibration through the stick shift. There was also a bad noise coming from the back of the engine. I could not tell if it was coming from the engine, the tranny or the clutch. The only thing that I could think of that could have hurt something was that I messed up a down shift and it revved pretty hard against the clutch once. It seemed like I smelled some clutch material for a brief time after that, but it seemed to shift and drive wihout problem for a long time before the fuel issue cropped up. At that point I decided to call it a day and limp home. I didn't get very far. The vibration got worse at 3,000 RPM or when I went above 60 MPH. I had to leave the car and come back the next day with a trailer. Not knowing where the problem was and not having time to deal with it, I decided to drop it off at a Z Shop as long as I had it on a trailer. He thought it was a clutch problem. Once he took it apart, he found that the ring of weights on the CenterForce II clutch had slipped to one side. This seemed to make sense, that if the weights were off center, that it would cause a vibration. I got the car back today. It still has a severe vibration that comes right up the shift lever. He thought it was the shift knob causing it. But I took it completely off and it still vibrates, so that can't be it. At this point I am starting to think some is wrong with the trans. Anybody got any ideas what would cause such a vibration through the shift lever? TIA, Marty