I plan on doing the clutch in my 95 525i (M50) this spring. 158K on the clock. Assuming the surface of the original dual-mass flywheel is in good shape, do I really have to replace the flywheel? I hear of a lot of people switching to a single mass flywheel on the E34, but I'd rather not incur the expense if its not needed. What is the official word on this?