Centric Clutch Kit

My car has had a vibration ever since I got it going. I'm convinced it is the clutch.
I bought a used Spec clutch kit when building the car and was told that it should be fine.
Took it to a machine shop for balancing, they said the flywheel was fine,
but with pressure plate bolted on needed a lot of weight to balance.
The vibration is the same. I bought a LS6 clutch made by Centric from a friend
who owns a very well respected shop that specializes in GM LS engined cars, he gave me
a great deal.
With both fly wheels sitting next to each other with just the pressure plates sitting on them
there is a different in heigth of the spring fingers the release bearing pushes on.
About .100 difference.
Now the centric PP is an auto adjusting type, I've had some experience with these on BMW's
I'm thinking the auto adjust may make up for the difference in height of fingers.
I guess my question is has anyone had any experience with the Centric clutches
that auto adjust on thier conversion? Or do I need to get a whole kit made for the conversion.

I had the same issue with my Spec Clutch and had to have it balanced. Turned out the clutch was off balance but that was not the issue with my vibration. While it was out I put in a LS7 clutch kit and it has an auto adjusting pressure plate. I have been running that for the last couple of years with no issue. I have been using a C5 slave cylinder. Not exactly the setup you have but close with the auto adjusting PP. Has not been a problem.