How many CFM for my 340?

I have a 360 that is producing approximately 370 HP. I have had a 600, 670, 725 and 750 cfm carb on it. The 600 gave up some noticabel seat of the pants power above 4500 rpm to the 725 and 750 but had it all over those two in driveability below 4500 rpm. For a street driven vehicle the 600 is the best choice of those three.

The 670 Street Avenger is the current carb I am using and is the one that has caused me to stop playing with carbs. It has every bit as much power above 4500 rpm as the 725 or 750 plus has all the driveability of the 600 rpm below 4500 rpm.

IMHO, unless you plan to race you are better off going with a smaller carb. Even the 400 HP 5.7 Hemi crate motors come with 600 cfm carbs.