FYI - There is an old style of CVEC pipe that is really hard to tune. It has a longer taper to it. The newer style (shorter taper) is the better of the two.

Do not use the rear exhaust header option (traps oil and makes the engine run terrible).

Shortly after I first got the pipe, some sludge stuck the piston shut and figuring that out was a pain. I pulled the piston out of mine (did not cut the cone) and it has been an awesome pipe. I am running it on a OS CV15 and it screams. I will be bolting it to an EPIC .18 big bore engine shortly.