Unless referring to a specific Walbro pump...they are just another gerotor pump like most all EFI pumps. (GSL-392)
The only difference in all of them is the flow rate and the inlet and outlet fittings.
Nothing I know of makes them any better at lifting fuel.
Most electric EFI pumps are listed as being capable of lifting up to 12" above the fuel level.
Most tanks are about 12" deep from top to bottom.
So with that you really should not mount the pump above the tank.
If mounted at or below the bottom of the tank then it will always have a syphon feed to the pump just like when you stick a hose in the tank to syphon fuel.
There are lots of ways things can be installed and made to work.
But there are ways to install them to to ensure proper operation and long life.
Twisting wires together and wrapping in duct tape may work but it certainly doesn't last!!
If you do a quick google search you will find most installations that have the pump mounted forward still run the stock intank pump to feed the new one.
Ford used this 2 pump system on the F series trucks where they use a low pressure intank lift pump to feed the frame mounted E2000 EFI inline pump.
