Model B Zenith Carburetor

[BRENT in 10-uh-C]

Well, ...Yes, -and No.

If you compare the two carburetors themselves you will see the Model-B has a larger venturi and throat which "should" allow more cfm of fuel and air. The "should" comes in that you will find the stock Model-A intake has a 1.00" rough cast draw tube. A Model-B intake has a 1.250" diameter draw tube meaing it will flow about 30+% more air. I realize someone is going to say well it is only ¼" larger in diameter however the airflow goes up on the square when the diameter is increased, and the bore surface of the B intake is different too.

I would suggest that you consider opening up your stock A intake and port match to the B carburetor, or install a Model B intake. The downside to the B manifold is the mounting flange on the B manifold is slightly canted requiring a little alteration to be able to connect the choke rod to the B carburetor. Hope this helps.