C6M6 LS2 VIBRATION in 1st GEAR
 

After a recent Clutch assy install I now have a vibration at 4000RPM
in first gear and less prevalent in second and third. I know the Clutch
must break in buit it still has me concerned. If I just rev the engine while
sitting it is hardly noticeable. The car is Cammed and I had the balancer
pinned about 3000 miles back so i can pretty much rule that out. Any ideas as to what is causing the vibration.

If it was OK before the clutch job and now vibrates after the clutch job, you can be pretty assured that the clutch is the culprid. I'd take it back to whoever installed the clutch.

:iagree:

Vibration rpm sensitivity
 

I checked a few things out to confirm what circumstances the car vibrates. At first I thought it was under acceleration only but in closer observance it vibrates starting at 4000rpm and normalizes around
5500. I talked to my installer and he said he would be only too happy
to pull the assy down. Before I do that are there possibilities of headers
/ muffler pipes touching the frame causing a resonant vibration ?. It feels like around the central part of the car. I checked out weather these assemblies are balanced when you get them and they are but I also heard that you should balance match the flywheel to your stock one. It does not seem like a practical thing to do when your car is on the lift waiting for the assemblies are to be done. I really need some help here from anyone who had a vibration problem and found it to be headers or something.

In short the vibration problem is not speed sensitive or acceleration sensitive which I first thought. it is purely RPM sensitive clutchin or clutch out.

I doubt you have a header/exhaust vibration problem. Easy enough to put the car on a lift and carefully examine to see if there are any frame rubbing issues. As I said before, no problem before the clutch job, now there's a problem, leads one to believe that the clutch job is the culprid. Since your installer is cooperative and will tear it down why not move ahead with that? That's sure what I'd do.