So I am converting all my vaccum lines and boost lines to AN fittings and or at minimum push loc style fittings and getting rid of all the traditional barbed fittings. So I every fitting so far on the turbosmart hyper 45 gate was dual 1/8 NPT thread, the P-TUning intercooler boost source is 1/8 NPT, MAC solenoid is 1/8 NPT, and of course the only thing that is not is the top of the turbosmart BOV. I figured it was a 1/4 NPT... so I got a 1/4 male to 1/8 npt reducer but the 1/4 NPT is just a tiny bit to big. Does anyone know 100% what thread and size the top of this blow off valve is so I can just order it online and not waste anymore time messing around.

thanks for any help offered.

 

I realize that this is an old post, but the thread pitch is 7/16 x 20 (-4AN). The metric equivalent is M12 x 1.75