exhaust comes in "stock trim" or "TRD
action package trim" otherwise known as "normal" and "extended". i was not aware however that there were any performance differences.
in any case, the TRD
exhaust will only give you about 5 horses whp. TRD
exhaust is also one of the lightest exhausts around (25 pounds).
the reason you will only get 5 horses from your TRD
exhaust is that you most likely won't retune your ecu. if you can afford to tune your car, then you will realize greater gains.