I had 18000kms/ 11200miles on my rebuilt before I sheared the output shaft. Upgraded to 4L65 planetarys, red devil cutches, beast sunshell, HD2 shift kit 1800 stall and vette servo. Blew the tires off when it shifted to second. Way awesome till it grenaded. Had current trans built same way but with a 2200 stall, haven't had any issues, mind you I'm a little easier on the skinny pedal now a days....