When converting your fuel system to a return style EFI setup, the biggest challenge can be plumbing the fuel lines. Holley continues to be the leader in fuel system development to make your life easier! The new Holley EFI Filter Regulator assembly simplifies your installation by combining the fuel filter and regulator in one assembly that can be mounted in the rear of the vehicle. Thus making your return line much shorter. The aluminum assembly contains a 175 GPH 10 Micron filter and a regulator preset at 59. 5 psi. The filter regulator comes in 3/8" NPT or 8 AN port sizes to match most EFI fuel systems.