Can anybody tell me the size of the Banjo bolt on the fuel rail that I'd need to hook up a fuel pressure gauge?

I think it is an M8 x 1.0 and I have seen one from OTC that appears to have a standard schrader valve type connector on one end for a normal pressure gauge. Has anybody used one? Can this type of adapter be used permanently for installation of a sensor & gauge? I'd like the ability to hook up a test gauge, but ultimately I'd like to have one permanently installed in the cab.

I read that many people apparently drilled & tapped part of the fuel rail on 22RE engines so perhaps I could do that, but this looks like it might work well.

http://amazon.com/s/ref=nb_ss_auto/...;amp;Go.x=0&Go.y=0&Go=Go