My friends Night Train is at about 50,000 and doesn't seem to need any work yet. It has been my experience that when they do need work it's the rear cyl. though. It doesn't cool as well being blocked by the front one. That isn't to say that the front one doesn't need it too just that the rear one usually seems to show more wear and start giving signs of wear first.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!