c5racing

I was trying to find out how much pressure the return line is under from the fuel rail back to the tank. what i currently have is the lines were cut in the engine bay to run a carburetor so im planning on running 6an hose and fittings from those lines to the fuel rail. i was gonna use these fittings at first http://www.jegs.com/i/Earls/361/165006/10002/-1 but im thinking maybe i should just use an-npt adapters and reflare and put nuts back on the hard line with compression fittings to attach to the adapters but cant seem to find one that will fit a 5/16 line they all seem to be 1/4 3/8 or 1/2 inch line other then these but they are only rated to 50 psi and dont look to be flared at all.

or any fitting suggestions would be appreciated i already have the fuel rail to 6an fittings in my shopping cart.

Z28TT

actually, the return line is typically under 0 pressure because the FPR holds the pressure IN the fuel rail, and allows 'spill-over' back to the tank. I would prepare the return line to accept the same amount of pressure the rail can support. You will never get the return line up to 45psi because the injectors are eating the fuel, but is good to be safe.

as for the fittings, you will need a compression to -an adapter to run steel braided lines, I had the same issue years ago when I still had the factory fuel rail in my TPI