T-valve... Where is it exactly?

[JiFaire]

So I take it I can use that line to hook up a fuel pressure gauge?

I wouldn't use that line; it's probably all dried-out. I would hook up a gauge to the nipple it comes off, though. Note that this is for a temporary fuel gauge, in my opinion... you need that opening to drain off water if you get any in your fuel (your WIF light will come on). If I was to install a permenent fuel pressure gauge, I would tee it into the main line between the FFM and the IP.

 

[Turbine Doc]

I wouldn't use that line; it's probably all dried-out. I would hook up a gauge to the nipple it comes off, though. Note that this is for a temporary fuel gauge, in my opinion... you need that opening to drain off water if you get any in your fuel (your WIF light will come on). If I was to install a permanent fuel pressure gauge, I would tee it into the main line between the FFM and the IP.

X2 do a feed the beast mod and when you are plumbing that you can put in a permanent tap at outlet of the FFM feed to the IP lets you know when lift pump isn't up to par, or that you have a filter blockage starving the IP of fuel