The stock 350z fuel system is a dead-head style setup. This means there is a single supply line from the tank to the fuel rails. The fuel pressure is regulated at the tank. While fine for stock applications this is an area that needs some improvement when mods are made, especially in boosted applications.
The factory rails were converted to work with a fuel return, and were plumbed in parallel instead of series. This setup allows for more fuel that is cooler and well regulated.
To do this the factory damper flanges and connector tube were cut off. Then the ends of the rails were drilled out to match the ID of the main fuel rail tube. To finish the rails and allow easy hookup to AN fittings and braided tubing steel -6AN male fittings were welded to the ends of the rails. These are available from Summit Racing for a couple bucks each.
Factory damper flange cut off:
I'm using an adjustable Aeromotive fuel pressure regulator as well as a small in-line gauge to make adjustments easy from the engine bay. Note the ProFlow 350 Hose, its nylon braided hose that it super flexible and light. I prefer it in the engine bay over SS hose which is stiff and abrasive.
As I mentioned earlier, the rails are plumbed in parallel and are fed by a -8AN line that splits into two -6AN lines. Each rail dumps to a side port on the regulator which in turn dumps to a -8AN return line that flows back to the tank.
Originally when I had the L28 in the car I ran two stainless braided lines from the tank to the fuel rails. It worked but i didn't really like the setup because it didn't allow for much flexibility. If anything needed to be changed or rearranged everything would need to be re-plumbed.
I decided to run hard line this time around. I am using 1/2" aluminum hard line that is terminated at the ends with bulkhead fittings on a bracket. I'm using stainless braided line in the back under the car and proflow nylon braided under the hood.
I kept my original fuel setup from the L28 which includes a Walboro 255 inline pump, Peterson fuel filter, and a Jazz fuel cell. In the future I would like to swap back to the factory tank setup and install an in-tank pump.
I used stamped stainless clamps and riv-nuts to hold the lines in place, they are made by Kugel Komponents (http://www.kugelkomponents.com/).