I put a Vortech S-trim V-1 on my virtually stock 360 Magnum and concurrently went from340 cast iron exhaust manifolds to TTI stepped headers, and a Chinese Air Gap copy. My quarter mile times went from 13.35 to Mid-11's and 102-MPH to 118. RWHP went from 260 to 445. This was with 10 pounds of boost in a 3,400-pound car