What fuel pressure does an LS need?

LS engines with factory-style port injection need about 58 psi of constant fuel pressure (Speedway Motors: 58–60 psi). A carbureted car's mechanical pump can't do this, so swaps need an electric pump (in-tank is preferred: runs cooler, no gravity-feed issues) and a regulator/filter set to 58 psi; a C5 Corvette-style filter-regulator is the common solution. Most swaps use AN-6 (3/8 in) fuel line.