4l60E + heads and cam....
Got my H/C installed in late February 2004, put close to 40 passes on it from then till mid November. Noticed the car started hitting the rev limitter at the top end then. Thought the car was just running out of gear till I had a few tell me I might be burning up the 3-4 clutches. Car drove around fine, never lost any gears, then in mid December went a head and took it out to get it checked and got some new parts put in. I didn't want to wait for it to get so bad I couldn't drive it. 3-4 actually didn't look too bad, but the forward clutches were starting to wear good. So, 10 months of driving and about 38 track passes later it was getting worn. It will be different for other cars though I'm sure. Before that we had hundreds of passes on the car with a stall and bolt-ons.
