The O.D. is the same on all these parts, it's the I.D. that is different. If I remember correctly the "O" ring for the TBis the same for either the 68mm or 74mm TB., the elbow is the same for either. The MAF and TB are 68mm and 74mm for both. I changed the MAF and the TB and took the baffles out of the elbow and the screens. I left the screen in the engine cover. I swapped the flow sensor in the MAF ( removed the sensor in the 74mm and replaced with the 68mm sensor). Got a few more RWHP, but improved sound and response.