I have a 1996 Impala SS that I would like to enhance it's performance, will the 4L60E trans still work or do I need to convert to a non-computer trans? Would like to hear feedback on the idea of swapping out the EFI for a carb.  Thanks  

You're not going to enahnce performance getting rid of your Impala's tune port injection system. If anything you'll hurt it.

You can get a lot of aftermarket parts for the TPI systems, like better runners, lower intakes, and other items. And because your Impala is OBD II equipped, you've got more tuning options for the computer.