hanman

I recently installed a low mileage used engine in my car. But, I used the clutch from the old engine because it looked to have more life left in it than the one on the new engine. So what I have is the flywheel with the new engine, but the clutch disk from the old one. My problem is that I have some clutch chatter in first gear. Any chance of this getting better as I put some miles on the car, or do I need to resurface the flywheel? I realize that I should have done this at the time, but I didn't, so shame on me.
If I need to resurface the flywheel, can I do it without removing the flywheel, what a PIA. If so, I am looking for recommendations on the best way to do this.
Thanks,
dave