IMO, the converter is way way up on the list of things that need to be "right".

When my friend was racing his gto as a bracket car, running low 11's at around 120mph, he thought maybe it was time to upgrade from the factory fuel line and Carter street/strip mechanical pump.

He went with a Mallory 140 pump/regulator, matching filter, and upgraded to a 1/2" line from pick-up to regulator.
Then 2 #6 lines to the carb.

Zero difference in performance.

I'm not advocating the use of marginal fuel systems...... But at the same time, you only need what you need...... And having more fuel system capacity than that won't improve your ET.