make like 3 hp less than kooks i belive? but for the price u cant go wrong i debated getting slps or kooks but my pacesetters do the job and fiitment is good just dont bolt the header down before reinstalling the steering rack its then a bitch. O and i would recomene a small miget to crawl into the engine bay a reconect the powersteering lines as they are a bitch, you might wnat to cut a wrench in half to get in there. I have heard this is an issue with most headers on gto’s