distributor cap and rotor - when to replace?

[oneway]

how do you know when it's a good time to replace the distributor cap and rotor?

[tekatlarge]

When the terminals in the cap get corroded, burnt, or damaged.
When the carbon button in the center of the cap is worn broken or damaged.
When there are ANY signs of arcing or carbon tracking inside the cap or obvious damage inside or out.
The rotor if the tip of the rotor is damaged corroded or shows any signs of carbon tracking. Or of the little spring type connection showing arcing, wear or damage. also inspect and replace the rotor if it has any cracks where it is attached to the distributor shaft or advance assembly.

[oneway]

Thank you

[drofman]

excellent post tex