I have the Exedy stage 2 it shook a little bit after install and when the rpms came down. I'm just now at 550 miles since my install and it's going away. Did you have the flywheel resurfaced? I think it's just part of the break in period. I set my trip calculator on my odometer to 0 to see when I reached the 500 mile break in period. When a new clutch is installed it takes 500 city miles for a proper break in and not shifting over 3k rpms. Normal symptoms of a clutch breaking in is chattering when engaging.