If you want to buy a less expensive header that will still make power then get this 4-1 (2.5" Collector) . It's looks just like the DC 4-1 (2.5" collector) and very similar to the Type-R exhaust manifolds. Just be careful if you're riding low, especially on an EF because the header scrapes! Currently on my 3rd one right now, except I got Charles (Mainstream) to build me a skid plate to protect it this time .