Some help with fuel line to Edelbrock carb?

[StoningtonQB]

OK, up until now I have been pretty embarrassed to show pics of my engine bay. For those of you who think, "it's not bad" keep in mind I have major OCD about things like this (I know the M/C looks like trash and needs to come out). But the biggest concern below is my fuel line:


Now, obviously the rubber has to go. I want to get a hard line with an inline fuel filter (then braided down to the pump). The question is what size fitting goes on to the fuel pump? I have heard that I should adapt it to -6 AN and yada yada yada. But there are a bunch of people all saying different things as far as what fits the original pump perfectly. I hear 3/8 IF, 3/8 NPT, 5/8 NPT so which one is it?

Then there is the question of whether or not to use both fuel inlets. The driver's side inlet is blocked off and the truck runs fine. Is there any benefit to getting the twin line kit? I will be using the factory air cleaner assembly so my air flow will be *somewhat* restricted even with a K&N drop-in. Thoughts?