It was in the car when I picked it up last fall....maybe a year old prior to last fall, as the cap/rotor had very little wear to them and old owner installed entire MSD system (6 AL Ignition box, coil, dist, wires).........seems to be a common problem with that distributor (lack of protective coating) and is mainly caused by ionization due to the higher energy spark they produce, is what I have found on the MSD forums.