Classic/Antique Car Repair: air and fuel mixture, fuel mixture, jet sizes

Question
what would the air/fuel mix be 4 a65 chevy with a 2 barr carb and 283 thank u

Answer
My response to this question was delayed by a system problem at AllExperts - I've reported this but so far have not heard back from them.  I'm trying to send this to you for the 4th time now!

The optimum mixture is 13 to 1, but only a computer controlled fuel injected system will be that accurate.  If you are setting the carburetor mixture at idle, try setting it at 12 1/2 to one and then see how the car drives. If it spits back or balks when you try to accelerate, it's too lean, so adjust it to 11 to one and try again.  You can't change anything other than the idle mixture with the adjustment, the jet sizes control the high speed and acceleration mixtures.

Dick