[40forddgc]

What is the best CFM for a carb on a 350 Chevy with 350 horsepower.

[DoubleVision]

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.

[heathj1]

I had a 3310 holley 750 vac sec on a 350 with turbo 350 and 4:10 gears. Ran great

[curtis73]

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.

[ap72]

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.

[40forddgc]

What is a ballpark for fuel pressure?

[ap72]

whatever the carb manual specifies, usually around 5psi. Sometimes as low as 3, or higher.