Two fuel lines coming off the tank. 1/4 and 5/16

[Kentstoy]

there are the two lines on my tank. I believe one is supply and one is return. The fuel pump was originally hooked up on the smaller line (1/4") and not the larger (5/16") one. I wonder if thats correct. I attached a picture.

[redroadster]

Yes , and 1/4 inch is being generous...it is more like 3/16" at the S bend near the connection ,and 1/8 "with some corrosion ,on my 70 spl