So theres a 02 z28 camaro but ive done some research and alot of people are saying that these auto trannys are known for being bad or going out fast is that true or does anyone have any advice on this the car im looking to buy has 120,000 miles on it

 

I joined this forum in 2004 and haven't noticed activity that the 4L60E are bad or known for being bad. If anything, they've been reliable for intended uses. Occasionally seen threads (not many) on broken forward sprags and 3/4 clutch packs gone/burnt (again not many). Heat causes problems and an aftermarket tranny fluid cooler is always recommended for playing/racing.
120,000 miles if has not been abused should still be working fine, abused could have problems. Dropping the pan and looking for pieces/sediment of clutch material could tell history. 120,000 miles should have a fluid and filter change anyway.