There are two fuel lines on the fuel filter (I think 3rd gens have one?) in my 2nd gen LS. I know that one is the fuel pressure and one is the fuel return. But I'm not sure which is which. Is it the one the goes to the rail or the one the goes into the firewall? I'm assuming it's the one that goes to the rail? I'm confused because the picture in my helms manual is the total opposite of what I see in the car. I just installed a B&M fuel pressure gauge to the line with the banjo bolt assembly, but that line goes into the firewall. In the picture it shows the banjo bolt on the thicker fuel line that seems to lead to the rail. The banjo bolt in my car is on the skinnier line. I'm confused....

 

you have your guage hooked up correctly. both of the lines that you refer to are under pressure. the fuel return is located where your fuel pressure regulator is (look for a hat shoed thing on your fuel rail).

 

Thanks.

The reason I'm asking is because I'm going to tap the line when I install my wet nitrous kit, but I wasn't sure which line. I guess I'm going to tap the line that leads to the rail.