The most common parts replaced during a clutch kit replacement are:
* Clutch plates (friction plates and steel plates): These are the components that wear out most quickly and are almost always replaced.
* Clutch springs: These can weaken over time, affecting clutch engagement.
* Clutch hub/basket: Sometimes damaged, but less frequent than the plates.
The flywheel's surface is important for the clutch to grip properly, but usually, unless it's badly damaged (deep scoring, warping), it's left untouched during a standard clutch replacement. Resurfacing is a more involved process and adds significant cost to the job.
In short: If your mechanic is suggesting flywheel resurfacing for a 1990 Storm clutch job, ask them *why* they believe it's necessary. They should be able to show you specific damage to justify the extra expense. If there's no visible damage, it's likely unnecessary.