Here's a really good rule of thumb to use for carburetor selection -
(Cubic Inches X Maximum RPM)/3456
All the "I've got a pair of 1050's on my 327" guys are going to wade in here screaming at me, but lets look at your application.
You have a 355" motor. What's the maximum RPM you see with this combination? Do you ever screw it up to 6,000?
(355 X 6000)/3456 = 616 CFM
Maybe you're brave and you run it up to 7,000? 719 CFM
8,000 RPM? 821 CFM.
9,000 RPM? 924 CFM.
10,000 RPM? 1027 CFM. Ahhh, now we're finally reached the flow capacity limit of your carbs.
But let's start looking at this realistically. What is the maximum RPM on this motor in normal driving conditions? I bet you rarely run it up to 4,500. That's 462 CFM.
300 of duration means a lot of overlap. A lot of overlap means a loss in manifold vacuum. A loss in manifold vacuum means a weak signal to the carb/s. Carbs are pressure differential devices and when a carb doesn't see much differential, it gets lost. So the carb is going to be sitting there waiting for air speed to pick up through the venturis before it starts to understand what the heck is going on. And that isn't going to happen until the motor starts to get upstairs.
I've been watching this happen for more years than I can count. A customer walks in the door with a wad of cash in his hand. His buddy told him to get a set of double-hump heads, a set of 12.5:1 pistons and a 302 camshaft, a tunnel ram and 2 750 CFM double pumpers for his street-driven 4X4 pickup with 33" tires and 3.08:1 gears.
What do you mean I will have to run race fuel in this engine, I plan to pull my boat to the lake with this truck. What do you mean I'm going to have to put lower gears in? Won't that kill my mileage on the way to the lake? And why do I need a looser convertor? And I think the stock valve springs will be OK, they still have 85 lbs of seat.
Start at the opposite end of things. How are you planning to drive the car? On the street? Long distances, are they a possibility? If so, then you are likely wanting to use pump gas. So a lot of compression is a no-no. Where is the motor going to spend the majority of its running time? At 3,000 RPM? Then build everything with that in mind, so the engine can be happy at 3,000 RPM. That means 'think small'. Small runners in the heads and intake. Small valves. Small cam profiles. Small carbs.
Need a visual to see what I'm talking about? Go outside, take the nozzle off your garden hose and turn the water on. Go ahead, turn it on full blast. How far is the water shooting out of the hose? Now, take your thumb and reduce the opening at the end of the hose. What just happened to that stream of water? Air does the same thing in a runner as water in a hose.
Same with intake manifolds. Take a plastic soda bottle and pull a vacuum on it with your mouth. See the bottle collapse? Now, take a five gallon jug and pull a vacuum on it with your mouth. Your vacuum ability gets lost with that additional volume, doesn't it?
Again, the bigger-is-always-better guys are going to flame me for this one, but don't let them fool you. If I just spent $10K on a sheet-metal intake and a pair of whiz-bang, double throw-down Dominators, then that is going to be the hot lick too. I don't want you to see me fuming because my investment won't work.
Do you want to have things look good? Or do you want performance to rip your head off?