Happy Friday!

Just performed a diesel purge and noticed upon reconnecting my return line (the one going to the tank that's shaped like a cigar) had a few small cracks near the clamps. In a pinch, I cut a length of 5/16ths fuel line that I had on hand for the purge and replaced it. Amateurish question I realize, but are the parts fungible? Is there any reason for the larger diameter of the original return line? Does it matter?