I have a 99 z28 roller i just bought a 5.7 ls1 for it my questions are what 4l60e transmission fits my car

 

Any '98 - '07 (some '08) 4L60E/4L65E/4L70E from an LS engine vehicle will fit and work with any LS1 PCM. Make sure the trans bell housing has a bolt hole in the 12 O'Clock position, which then indicates it has a 300mm input shaft. Obviously need an LS converter too.

Post #2 has a picture of what you need:
https://ls1tech.com/forums/automatic...uld-i-buy.html