well all i know is it fit right up to it because the guy i baught the car from put it on and he had to make a new hole for the o2 sensor so right now it is ok but the sensor is in the wrong spot so i am going to be getting a new header for it soon, ( preferably one that goes to my car and motor ) but yes it does fit, and actually i mad a mistake on that cause i was a little steamed by all this swap stuff, it is actually a b18 header, so i dont know what to tell you but that is what it is, believe me i didnt think it was either cause there should be no way that a b16 anything would match a d series but hey some things just work out that way...