No, you are running very low pressure, so you need a larger diameter tube to provide the volume. 1/2" is what most people use. Why do you need a return line for a carb with a blue holley pump? They are designed to be returnless.
I ran 8AN from the the Blue pump in the back to a non return regulator in the front. I ran dual 6AN from the Reg to the carb inlets. Works Good!
And If I plan on going bigger with a return sytle regulator I would use the 8AN for the return and 10AN for supply.