New guy--fuel lines

New to the board.

Fuel line question. To go carb convert I should use larger line and pickup tube. Example 3/8 for 300 h.p. streeter no track. No problem. Stock line for my 86 is 5/16 with intank pump. Wonder why that fuel line works for 100h.p. nitrous shot on stock setup as venders say, but need larger line for carb. Is it that some folks bolt and go using larger pump only on f.i. Set me straight. I confuzzed.

Thanks

Thanks guys.

Now next question. I need a 3/8 in tank fuel pickup line. Another board sugested making one or getting an after market one--$120. Does any older year carb car have a direct install? 85 stang pickup tube was a choice but hard to find. I will be running a mallery 110 pump.

Later