I have a 97 mustang gt with a 03 gt engine. I know someone that upgraded the blower(Roush blower) on there mustang so he is sell the upper half of the blower cheap. Is there any web site that I can buy the rest of the parts such as lower intake,brackets,etc? Also how much power can i expect to make with a stock pully with full exhaust, intake, and tune. I have been searching but everything is really coming up for 05 and up.

 

I can't answer your other questions, but i can tell you that "stock" 99-04 stage 3 Roush's are not very fast at all! I raced one on the e-way (the guy shouted to me that it was a stock stage 3) and he barely got me by the top of 4th. Mind you my n/a rear wheel horsepower is only 270.

With the stock pulley, and full exhaust, intake, etc, i'd be surprised if you got over 350 rwhp...that's being very generous! Maybe i'm wrong on the numbers, but these things are dogs from the factory!