Back Electrical Fuel Pump O-540 with Carb

[Airplane3472]

What pump is being used as a backup electrical fuel pump on a 4 place with Lycoming O-540 with Carburetor? The engine has a engine driven fuel fuel pump installed but need backup electrical. Trying to maintain the 3/8 tubing size and most low perssure 4-7psi (for carburetor) Facet pumps all seem to have the smaller 1/8" fitting size. Any suggestions?

 

[jaredyates]

You might try the facet pumps that are cylindrical-shaped instead of the cubes, since they stopped making the cube that we need.