Originally Posted by Chad Millikan

Each collet might be different from manufacturer to manufacturer, weather it be the cone pitch or length. Pick the one or shim it to where the flywheel is as close as possible to the case without rubbing. Then add the bell with bearing and add one shim at a time till you can spin the bell with out it rubbing on the flywheel. Then finally shim the play with shims on the front of the bell. .94mm of play is what Monty recommends .