fuel sending unit size??

[highstyle2]

Redoing entire driveline on my '73 SE, have a 400 BB, going from OEM 2bbl to 4 bbl. I want to replace fuel tank & sending unit, wondering what was OEM size on sending unit, 3/8" outlet or 5/16". Should it be the smaller size, would the larger size be the sensible swap with the 4bbl. Thank ya veddy much.........

[DixieRestoParts]

400 was 5/16" OEM. You can go to 3/8", but to really take advantage of the increased capacity of the sending unit, you need to upgrade the fuel line from the tank to the pump also.

[highstyle2]

thanks for the help, appriciate it.