73 340 carb replacement ?

[Randy73]

Stock carb leaks air at the butterflies, so I am going to replace it, unless there is replacement bottom plate of the carb.

Was thinking of either getting a 600 or 650 carb, which would work better?

Also, I have heard that the stock intake is better than almost all , is that true?

TIA

 

[Coronet 500]

I've heard alot of guys don't like the Edelbrocks. Thermoquads, love 'em or hate 'em, I like them but prefer a Holley everytime. Go 650 for sure. Those 340 manifold are good.

 

[Randy73]

Would 750 be better?
I know it came with a 800 cfm.

 

[Coronet 500]

Those 800's have an air door that only allows them to flow as much as the engine will draw in. 750 will need big cam and be less streetable unless your going all out with the whole drive train.

 

[74sundance]

The rule of thumb is CI x 2 so 340 x 2 = 680 then you round down to the closest carb......600cfm. A larger carb will do you no good, unless your building a fire breathing beast you will just be waisting fuel, under powering your car and fuel washing your cylinders.

Here is another way to pic your carb size:
You take the engine cubic inch and multiply by the maximum RPM and divide by 3456. If you have an automatic transmission you will need a vacuum sec. carb, a standard transmission can use a Double Pumper carb.
So 340ci x 6000 RPM = 2040000 / 3456 = 590.277 CFM