If it's carb, 6.9 or 7.3 there isn't much to worry about, just a return line to the tank. If it's EFI I leave everything in the tanks if the pumps work and knock the guts out of the fill necks. I install a jumper wire from the ground side of the fuel pump relay to ground, this will make the fuel pump(s) run any time the key is on. I don't regulate the pressure, instead I do it simpler (firm believer in KISS), what I prefer to do is build a simple 4 way fuel line intersection with brass fittings right off the lift pump inlet and connect both the supply and return lines into this.
The 4 way setup can be done anyway you like, but the design idea is that the supply line feeds straight into the lift pump the supply lines are BELOW the return lines and there is a small restriction orifice between the supply and return sections, say 3/32"-1/8". This setup simply supplies the lift pump with a small amount of head pressure that can't overpressurize the system. Also, because the supply is on the bottom, any air bubbles will go up or stay up and get returned to the tank instead of recirculated.
It is still easiest to use diesel tanks and lines, but the electric fuel pumps actually make troubleshooting and bleeding the fuel system really nice and easy. I've done many 90's gas fords like this and haven't had any issue with the fuel system. These fuel pumps aren't known for being the most reliable, but I have a feeling they actually like pumping diesel more than gasoline.
Also, the hard plastic EFI fuel lines can be reused, you don't need to gut them out. They work on standard hose barb fittings by heating with a heat gun and pushing on. Use a hose clamp though. I leave the EFI fuel filter in the lines. They're pretty cheap (cheaper than the cummins filters), decent size for a mild cummins and filter decently.
