I'm going from a tbi to a carb. Do I have to change my fuel Line because of the return line. Also do I have to change my trans.

 

Do some searching on the forum and read about what other people have done. It will give you an idea of what you are up against. You will need a fuel pressure regulator that will work with the return line. You will also need a non-computer controlled distributor ( I like the gm performance HEI). You don't mention which trans you currently have. If it is a 700R4 automatic, you will need a way to lock up the converter and also a geometry corrector for the carb where the TV cable will hook.