I don't know what the rules are for pure stock, but big block trucks had bigger fuel lines. I suspect cars did too.
Qjets can run low on fuel volume in the 1/4, increasing pressure isn't the cure, Volume is.
Where the sump is, line size, Can you run a high volume booster pump near the tank?
What pump is on the motor?
Still got the internal filter in the carb? Screw on inline filters have much more flow and micron rating.
Major acceleration and steady turns can force gas away from the pick up and does it have a screen on it? You want the pick up in the high pressure area.
It has already been said about float needle/seat size.
My list doesn't have that number, 7044227 CHEV 74 454 SUBURBAN, then then 62.
Swap enough parts and get any combo.
If you are serious get a couple books, Cliff Ruggles, Doug Roe I am sure these will tell you more than you ever wanted to know
DS