I had a Spec Stage 1 clutch/flywheel installed and ever since the install my car has been vibrating at idle. If I rev to exactly 1000rpm, the vibrating gets roughest. It seems to smoothen out at 1200-1300rpm. I don't notice it while driving.

My mechanic rechecked all the bolts and said there's only 1 way to align the clutch so it can't be off. New clutch has 700 miles on it.

I called up Spec and they said to return it. I don't want to get the clutch back and have the same problem. Is there any last resorts to fixing this problem before sending it back?