Why not rebuild the carb that you have?
Ford 801/4000 basic carb rebuild kit
Ford 801/4000 comprehensive carb rebuild kit
You can also go with a rebuilt carb for about half the price of a new replacement:
Ford 801/4000 rebuilt carb
They changed the diameter of the fuel line at some point and the fitting sizes changed accordingly
1/4" diameter fuel line
5/16" diameter fuel line
And there are two fuel shut-off valves depending on the fuel line diameter:
Ford 801/4000 shut-off valve - for 1/4" fuel line
Ford 801/4000 shut-off valve - for 5/16" fuel line
Ford 801/4000 basic carb rebuild kit
Ford 801/4000 comprehensive carb rebuild kit
You can also go with a rebuilt carb for about half the price of a new replacement:
Ford 801/4000 rebuilt carb
They changed the diameter of the fuel line at some point and the fitting sizes changed accordingly
1/4" diameter fuel line
5/16" diameter fuel line
And there are two fuel shut-off valves depending on the fuel line diameter:
Ford 801/4000 shut-off valve - for 1/4" fuel line
Ford 801/4000 shut-off valve - for 5/16" fuel line