I'm looking at getting a new transmission since the current one is getting to its limit. The car is mainly street driven but does see the strip time to time. Right now the car is full bolt on but I am hoping to rebuild the engine sometime soon. Will be going 383 hoping to make around 450 hp N/A. I'm not sure which company to go with as far as getting a transmission. I have heard a lot about RPM and FLT, and I feel that going with them may be the best spent money. I don't have a lot of money to spend but I want to make sure I can get the best now and not have to worry about problems in the long run.

 

This gets discussed here over and over and over again. You can search for references to the various sponsors.
Here is another thread just a few days old:
https://ls1tech.com/forums/automatic...ilt-4l60e.html