Return Fuel Line?

[FLcustom10]

Do I need a return fuel line? I'm ordering new fuel lines and am confused on whether I need the return line or not. The truck is torn down to the frame and I'm not sure I remember what all I removed... I remember taking off the fuel line and the vapor line, but I don't remember a return line. It's a 1972 C10 with a 307 v8.
Also - I'm going with 3/8" fuel line. I'm not sure if it was 5/16 or 3/8 before. Are there any concerns in case it was 5/16 before?

[butters_72]

my 1972 c10 350 has the tank behind the seat and the two on the sides of the bed and it has a return line that runs to the maintank behind the seat and im running 3/8 hoses, you can always just look at your fuel pump, if it just has two fittings then theres no return if it has three then on of which is the return hope that helps

[chewychevy67]

67 was the last year for 5/16 in the trucks. 68 used 3/8 because of the introduction of the big block i believe.

[FLcustom10]

Good answer! I just checked the fuel pump and it only has 2 fittings so no return line. Thank you.

[butters_72]

no problem glad i could help good luck with your rebuild

[Longhorn Man]

inlines, and 2 bbl trucks used 5/16ths line through 72. All big block, 4 bbl small block, and all V6 engines used the larget 3/8ths line

[LostMy65]

I asked this in another thread, but I think this thread may be more on topic.
Is there a benefit in running a return line?
Most all newer chevys have the 3 port fuel pump.
If we don't have a return line, is it a big deal?