an electric fuel pump needs to always be mounted at the low point of the fuel supply line. they pump fine but not against an air bubble that forms in the line from the upper level of fuel in the tank to the mounting location of the pump on the firewall.
any electric fuel pump needs to be mounted at or near the lowest point of the fuel supply.
most of those low pressure in-line fuel pumps will run 15 to 20 psi while most carburetor float bowl inlet valves like between 8 and 12 psi fuel pressures. the flow rate is generally indicated by the cost of the pump and it's inlet and outlet diameters.
i'm not a mk1 enthusiast so my remarks are just general. i never take being corrected by the mk1 godz very hard because they know best.