Fuel delivery is a critical part of any LS Swap. Most older, carbureted engines required significantly less fuel pressure than a modern LS style motor. That being said, you’ll need to find a fuel pump that’s suitable for your application. Your application may also need a fuel pressure regulator, and often the regulator can be combined with a fuel filter.
Fuel lines will need to be able to handle the increased pressure from stock systems, therefore hard lines or stainless steel braided lines are often used for LS swap applications. Many LS systems require a return line, and the routing of one or two fuel lines needs to be taken into consideration.