Carb Performance Question

[Aubrey3]

I have a 352 with the 2100 on it. From my understanding it is a 300 cfm carb with the 1.14 venturi size. I do not tow or race it. It's a daily driver around town and on the highway running 75 mph or so. I am in Denver with thin air.

My question is what kind of performance change would I expect if I switched out the carb to a 1.23 or 1.33 venturi size (351 cfm, 424 cfm)?

[Madman]

What are you trying to achieve? Better fuel mileage? Acceleration? Low end Torque? I believe you need to narrow down to what you want to achieve to answer the question properly.

[Aubrey3]

My desire would be all around performance gain and not so much mileage.
But I'm generally curious if the slight increase in carb size would change anything at all. Or on bottom or top only, what area suffers and how much.
I'm looking at 352ci * 5000rpm / 3456 * .7ve = 356cfm. I figured max rpm would be 5000 and ve would be no more than 70%. At 80% ve it would be 407cfm.
So maybe a 1.21 or 1.23 size venturi might open up a little more power in her? The 1.33 is probably too big especially here in Denver.