The whole LT1/4L60 setup is stock internally. It came out of a '95 Caprice state-patrol car that was totalled with 21k miles on new engine and transmission. (trans had a goodwrench sticker on it... engine is probably goodwrench also)
I'm sure the transmission will need to come out again for repairs in a couple years, but I figured with stock heads/cam on the engine, it will hold up for a while. If I can afford it, at that time, I may stick a 6-speed in
