Ah, the old Opti-spark problems.

I have yet to see anyone post an issue with the opti-spark distributor rotor wearing against the cap. I bought the car with 95k miles on it. It has gone through 3 caps/rotors in 8k miles. It appears that the rotor is being pushed into the cap causing it to melt then get destroyed. The latest one is a brand new complete opti-spark distributor.

I have yet to take it apart again to check play in the cam shaft. I can't imagine it is shifting front to back. I am not looking forward to taking the front cover off and removing the timing chain and cam sprocket. Generally, the car runs excellent until this cap/rotor issue comes up.

Note: take care of these issues quickly as one of the times it failed, it took out the entire ignition and burned up the catalytic converter.

 

If the cam was changed somewhere along the way, the distributor drive pin on the cam may be too long. You can gently tap it back or grind it shorter. Older LT1s used a shorter drive pin than the newer models.