SRT 6 Sevice Manual Section 14 fuel system. Here are the pages P.2940 2947thru2950 2954 & 2955.

If you look at the fuel filter it has two fittings on each end. Looking at the filter from the back of the car the bottom fitting on the left hooks directly to the fuel pump. The hose on the opposite side is the supply line for the fuel rail. I just hooked them together and presto full pressure to the front of the car. The hose that hooks up to the middle of the filter on the input side is the return line to the tank and the hose opposite it is a atmospheric line to the pressure regulator so it can compensate as you drive thru different elevations. You will need to run a high pressure fuel line from the factory return line up to your new pressure regulator. If you try and just block off the return you will be pushing betwee 80 and 130 PSi. How do I know this because that is how I did it at first and the lowest I could get the pressure was 80 PSI. Hooked up return line and now I have full control.

I cut the fuel line under the hood and installed the new fuel filter and regulator right there.