The best way to get the most out of a clutch in these old cars is to buy a new clutch quadrant and clutch cable first. This will allow factory tension between the TOB and pressure plate fingers, decreasing the chance of finger wear compared to the old parts. Then, never rest your foot on the clutch pedal at any time, and keep the clutch slipping to a minimum. The clutch disc only wears when it is being slipped (example: riding the clutch pedal out to get going from a dead stop), not from taking the rpm's up to 7k. And lift up on the clutch pedal from time to time to keep the cable properly tensioned, as it will self adjust. A good ideal time would be at every oil change, and after some street racing or track runs.