Hi I ended up buying it of the original poster ,as for fittment it is tight through the cat area and over diff cradle ,it expands a fair bit so you have to adjust it hot since it won't knock when its cold/warm takes a few goes ,sounds awesome 100 timed better than the xforce 3.5 that I had before and no drone with a deep note .This is on a bf2 btw it made 360rwkw on 15 psi,hope this helps