LS1 in e46 fuel linw configuration?

[schema]

I know I'm over thinking this- my ls1 fuel rail doesn't have a return (single inlet) , e46 has two lines going to the engine bay ( one appears to return to the fuel filter under the car).

How do I go about setting this up?

[unnatrl]

If it's a naturally aspirated setup you could use the Corvette fuel filter (has pressure regulator built in). The inlet line and a return line (to tank) are on one side and the other side connects to the returnless LS1 fuel rail. It's a clean and simple way of doing what you are asking.