All I need to know is, what is the measurement of the header donut on the down-pipe. I need it for a DC 4-1 header for a B16 CR -X, I was told that a NSX will work fine, but Iam a lil bit skeptical about this. I measured the outer and inner dimensions and came up with 2 and 9/16 I wanna see if NSX will actually work. TYIA.

 

Try searching for that in NSXprime, did you go to the NSX so cal drive a few weeks ago?