doing the math, figure 15-20 from a tune (i think some first gens got 24) 15 from a cai, so call it 30 plus 15 from a cat back leaves 15 from the headers. so they are expecting to get 30 from headers back system. sounds like similar gains to the magnaflow from catback and then again from headers/cat. similar pricing too. like i said i am looking into this. i may need to become a dealer to get the group buy, and the number he would like to see is 10. this is an ongoing devlopment im working on. i'll keep everyone posted. if you are serious about wanting these headers pm me. keep in mind they list from 800-1400 and discounts havent been figured out yet.