Right after I bought mine from JMTC, they told me they were changing their ICI pipe fabricator --- possibly 'cause I crabbed about the way the WMI port was added. Also the built-in "dent" to minimize an interference fit, is in the wrong location --- there's serious interference! Arric probably couldn't find another source to fab it at a reasonable price --- it's a really tight fit, with a couple critical bends. I suggest you take your car to someone that works with pipe, and have them custom-build one for you. Performance gains are noticeable on the butt dyno, plus Arric had a chart showing the HP gains, but it probably went away with the pipe.