fuel vent size

yea the pump is below the fuel cell........Cell is mounted in the trunk, and pump is mounted on right rear frame.........the filter is a 100 micron, 8 AN....distance from cell to pump is about
3 ft.? only limiting factor going to a 10AN is the pump has 3/8" threads.......... I just replaced a couple fittings on my regulator today...I had 1 inlet and one exit that were the close bend 90*, installed the pipe bend sweep 90*, Read somewhere that they can cause restriction and durbulence, so have to see how that goes. Car is a 67 barracuda FB, 318, air gap, 10/1, .244 @ .050, .501 lift, 750 demon, pocket ported 1.94/1.60 heads...904 tranny with a hughes 4500 stall, 4.56 gear, mopar FBO dist. MSD 6T, Soft touch rev, and dial a timing, MSD E-coil