I have the bracket that mounts to the hood, just need to see pics of how you guys ran the line out of the back of the gauge. I have an Auto Meter Pro Comp liquid filled gauge and mounting cup.
i have a black 180degree fitting for the curve then hose clips holding it to the underside of the hood til it heads twards the schrader tee on the fuel rail.
I have the Kenne Bell guage...pics of the gauge aren't mine but looks the same as this...U-shaped fitting out the back of guage...pic with car you can see the gauge with lines coming out back
I'm pretty sure I used a -4AN on mine with a hose end. I use a stainless one, Earls I think. You could always call Autometer tech line with your model number and they will tell you for sure what fitting will work.