Ive got a vortech super quiet, and u would never know my car is SC'ed...The most you are going to get to(not counting heads/cams, they are more than a s/c and not as much power) is about 340-360 rwhp depending on what dyno ur on..Not enough to keep up with older cobras,vettes, Gto's with mild bolt-ons...This has been a discussion on many forums, including this one, that there is only so much u can get out of these cars n/a..On the other hand, they respond great to forced induction and a dyno tune ..The exaust and intake/heads flow remarkably well on S-197's rather than older 5.0's, and S-197's dont respond to heads/cams and intakes like older models do...$3,500 gets u a full Vortech system(non-cooled) with 39lbs injectors, 255lph fuel pump, flash tuner if u dont have one..About $1,000 for labor and dyno time, and u have about 430 rwhp(DYNOJET)..plenty to pull on non C-5/Zo6 vettes, 03-04 stock cobras, and GTho's..