What do I need for fuel delivery on an LS3 swap starting from scratch with a fuel cell: pump, filter, regulator, surge tank?

A proven LS swap fuel system (Speedway's guidance):

• Pump: in-tank is best — the fuel cools and quiets it. An external electric pump must be mounted low, below the tank, because electric pumps push fuel rather than pull it.
• Filtration for EFI: a 100-micron pre-filter before the pump and a 10-micron filter after it.
• Regulator: a Corvette-style filter/regulator (58 psi, short return near the tank) suits mild engines up to about 450 NA hp. Bigger power or boost needs a dedicated regulator.
• Lines: 3/8 in (AN-6) is a good upgrade over stock 5/16 for street and mild race cars; 1/2 in (AN-8) for big power or alcohol. Avoid rubber line, keep lines away from exhaust heat, and use two 45° fittings instead of one 90° where you can — a 90° adds restriction like several extra feet of line.
• Pressure: LS EFI runs about 58 psi, so hose and fittings must be rated for it.

With a fuel cell: an in-cell pump works like an in-tank pump. If the cell can't take one, mount the external pump below the cell outlet, or feed a surge tank with its own high-pressure pump.

Sizing: Speedway's rule of thumb is about 0.5 lb of fuel per hp per hour naturally aspirated (0.6–0.75 with forced induction). Size the pump and injectors with the fuel system calculator.