You can in fact get away with the stock single fuel line with no return line. HOWEVER, as mentioned above, you WILL need a better fuel pump. Here is a trick that I learned and have shared on this site several times. Buy a stock fuel pump for a 1973-74 Pontiac SD (Super Duty TransAm) 455. The gas resevoir on the bottom of the pump is about 3-4 times bigger than a stock fuel pump for any other Pontiac engine.

Then, if you want to use a stock metal hard line to connect the fuel pump to the carb, order a pre-bent pump to carb fuel line for the same car (73-74 455 SD). This will solve any potential fuel delivery issues. Simple solution as everything fits and you are using stock parts. Guys will tell you that you need to run an electric fuel pump etc. Not true. The old 455 SD TransAm ran just fine back in the day with no fuel delivery issues...