I am running the Apexi SAFC on my SVT. When I got my car dyno tuned, I had minimal mods. Intake, resonator removed, and lightning MAF. I didn't get a big horsepower increas (1-2) but driveability improved tremendously. It pulls real hard all the way through 5th gear now. If you or anyone else is interested in it let me know. I'm going to be going the Xcal route. Thanks.