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NASCAR guys make a ton of power with 390 cfm carbs, of course they have a few tricks but they are really 390 cfm carbs.

I think a 500 cfm carb will work just fine on a street driven 440. The power would be down a little bit at WOT but probably not more than 10 or 20 hp from a 750 or 850 carb. This is assuming it is a street motor with a mild cam and pump gas compression.

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I'm conservative as far as carb size goes.
I even run a 625 road demon and my 440 tow rig winni, and find it is a great carb....

BUT 500 is way to small.

I remember I had a 600 eddy on a 400 with some mods. Threw on a 750, and saw a 30 wheel hp gain on a g tech.

I agree with running both.

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TQ arent cool, they'll never catch on.

the sportier carter would be the AVS.

the hollies DP750 on 440 will kick some butt. the 800 AVS will keep up, and is much easier to tune.

AVS has a longer pumpshot good for highway gears too. for cruising the avs wins.

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TQ arent cool, they'll never catch on.

the sportier carter would be the AVS.

the hollies DP750 on 440 will kick some butt. the 800 AVS will keep up, and is much easier to tune.

AVS has a longer pumpshot good for highway gears too. for cruising the avs wins.

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W/ AVS! and best mpg, if some care. Performance is why I like it, mpg is nice side effect. TQ is ok.

there is an equation to determine proper cfm but obviously 2bbl's work(especially 3 of them!)

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excellent thats what i have on my 440's action + top end... a edelbrock thunder AVS800. works great, i put the spring loaded high flow needle and seats in ,and checked the float level. the rods and jets are a snap to tune in. easier than a holley, but im more familiar with holley's. the carb is the best AVS unit i ve worked with.

make sure you know how to set the high idle on the choke and it will start right up.

the mechanical secondary kick in nicely on a 440.

my other 440 top end is a 750 SD demon on a RPM intake. that runs rich low, but fine top end.

i tried the dominator single and it was terrible on the street. ..nuff said.

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Are you saying your AVS (Thunder) doesn't work well with the Street dominator manifold? I always found it to be one of the best combo's out there. I have a manual tranny though so it is easy to launch.

Well the fact that there are some assumptions necessary is the reason to use the equation for volumetric efficiency as a guideline, but the equation itself isn't what I would call bogus. in a controlled environment, it carries some legitimacy. It just isn't that easy to control your street car.

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IMO, a double pumper is a great way to waste gas on a street car.

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That's because you don't know how to tune it...lol
any 4bbl carb will be a waste if you foot is heavy. and why would you have a 440 and care about mpg's? FWIW I managed to get 13mpg hwy in a 67 coronet (440) w/ 3.91's doing 70.

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The amount of misinformation on this board about carb sizing is staggering. Any performance carb will supply "enough gas" to mix with the air that can flow through the carb. The 500 cfm carb will support about 300 horsepower. That's using the rule of thumb of 0.6 hp per cfm.

Thousands of 413s ran millions of hours with two-barrel carburetors, pumping water and performing other industrial tasks. As I have said in a previous post my family car in the early '70s was a 2-barrel 455 olds which would run 90 in the quarter and would top out over 100 mph, the fastest indicated speed I ever saw was about 122 but the stock speedometer could have been lying too. (Growing up in North Dakota had its advantages in that there was hardly ever a cop around on the roads I drove.) The carb on that car was the larger Rochester two-barrel which I doubt flowed more than 375 cfm rated as a two-barrel carb, which would be about 265 rated as a 4-barrel.
Keep in mind also the thousands of dirt track racers using the Holley 4412 500 cfm 2-barrel, which would be 353 cfm rated as a 4-barrel.

Stick on a 500 instead of a 750 and you are leaving about 100 top end hp on the table. This power loss should all be above the torque peak. The car will run really strong until it "runs out of breath" which will be a disappointment but will not be accompanied by any expensive noises. Try it and see what you think. You can always buy a bigger carburetor later.

R.

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Especially with that misinformation part..

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A good running 440 will love a 750 DP. Your choice of makes. IMHO, anything less than a750 dp will cause your 440 to stumble and fall when you floor it, as it screams for more gas. scott

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A six pack screams on 2 barrels, until the outboarbs kick-in. You are only going to notice a small carb holding you back on the top end. Low end will be a blast to drive, it's not going to stumble if it's tuned properly.