-6AN or -8An fuel line?

If you're sucking from the tank, the bigger fuel line may help. But if you have a fuel pump in the rear, I don't think there will be much pressure drop in a -6 vs. a -8 and the smaller line is easier to route. Consider that the needle and seat in each bowl is only .120 or so in diameter. Two of those openings is much less area than a single .32 fuel line, so will be the biggest restriction.