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Old 12-13-2009, 03:34 PM
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carborater CFM recomendation question

What is the best CFM for a carb on a 350 Chevy with 350 horsepower.
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Old 12-13-2009, 03:49 PM
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Any 650 to 750 carb will work fine. However, There is a CFM formula where you can calculate what you need, if you use this method you`ll find the number is far lower, usually in the high 500`s which would work but likely wouldn`t be enough in the upper RPM ranges. I say slap a Quadrajet on it.
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Old 12-13-2009, 04:08 PM
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I had a 3310 holley 750 vac sec on a 350 with turbo 350 and 4:10 gears. Ran great
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Old 12-14-2009, 07:30 AM
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I would personally not go above 600. The 2 hp you gain at redline tends to be more than offset by greater difficulty tuning and potential loss of low end torque due to the slower velocity.
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Old 12-14-2009, 07:40 AM
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If you run a well tuned professionally built carb you can get away with much more carb than just going with a box stock unit with a jet change. IT all depends on what you want and what you want to spend.

For using a box stock carb max cfm should be about 2Xdisplacement (in CI), for most street engines. Another rule of thumb is max hpX2=cfm.
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Old 12-14-2009, 09:03 AM
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What About Fuel Pressure?

What is a ballpark for fuel pressure?
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Old 12-14-2009, 09:19 AM
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whatever the carb manual specifies, usually around 5psi. Sometimes as low as 3, or higher.
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