4L60E Transmission options
Cahall Performance Transmissions seems to have a lot of good reviews on the LT1 Facebook page. He's a pretty active poster on there too and is who I'll probably go with once I have my '94 4L60E rebuilt. But I too have heard bad reviews about Monster.
Like mentioned above a lot of people use Frank Cahall and seem to have good luck I think he's probably the cheapest option. Then next you would have Performabuilt and finishline, they both seem to have customers that have had mostly positive experiences but there are some people with negative experiences so would require research on your end to determine if you feel comfortable. And finally the most expensive and popular choice would probably be RPM who maintain a pretty stellar reputation and are arguably the best.

