Cobra Upper

I know of a stock 94-95 Cobra upper intake and stock throttle body I may be able to get my hands on. My questions are: What type of gains could I expect with just the upper? and would the swap be worth it for my car? Lastly, what is this setup worth?

Thanks in advance

EDIT: I have been informed that I need a cobra lower to make this work. For those of you that have the Cobra upper & lower on their GTs, what types of gains did you see?
Thanks

Thanks for the heads-up, Jason