Just to throw a little more fuel on the fire, so to speak, I had to give my dad a call. Im more into original stuff and hes an old hotrodder at heart.
He used to run a 427 with a 6-71 blower and two 4 barrel carbs. If he remembers right he only used 1/4" lines, and he said it had no problems with being starved for fuel. But having a blower also increases the volumetric effieciency of the fuel.
While my belief is that 5/16" is fine, you certainly cant hurt anything by going with a larger size.
gofstbuick, do you have any pics of your truck? We like that sort of thing!
