4 to 6 pounds will overdrive the float system in the original carburetor.

If you are going to use an electric, a pump that may be used is Federal Mogul / Carter number P-60430. This pump is self-regulated for 2 to 3 pounds at 6 V.D.C.; and has a capacity of 20 gal/hour rated at 2 psi.

Electric pumps are pusher pumps. One would probably push gas around the world, but it woun't pull 6 inches. Mount below the fuel tank on the frame, so you have gravity feed to the pump. Be sure to install the inline filter in FRONT of the pump (between the tank and the pump)!

Others have posted already concerning the electrical wiring (permanent controlled by oil pressure switch, with manual pushbutton override).

Do not run through your mechanical pump. Remove the mechanical pump and install a block-off plate.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop