Economy can have multiple meanings.
Initial cost:
Carter, Rochester, Stromberg, and Zenith all made carburetors for the Chevrolet 235.
The Rochester would have the lowest initial cost for a core, and maybe the highest cost to have that core professionally restored.
The Carter would be the next lowest cost for a core, and probably the lowest cost for a professional to restore the core.
The Stromberg and Zenith would have a much higher initial cost, and a higher restoration cost than the Carter, but much lower than the Rochester.
Fuel economy:
For a professionally restored carburetor, the Stromberg and Zenith might be 10 percent better than the Carter, which might be 10 percent better than the Rochester.
Reliability:
Again, for professionally restored carburetors, the Rochester MIGHT go 5 years without another full restoration, the Carter would probably go 5 years without a clean-out kit, and 20 years without another restoration.
The Stromberg and Zenith could be expected to go without service for maybe 100k miles or more, assuming fresh fuel was delivered to the carburetor.
Summary:
Lots of folks like the Carter, as a REBUILT, not RESTORED carb is relatively inexpensive with good fuel economy and reliability.
Leaking at the throttle shaft:
Re-read Carl's response above. Fuel leaks around the throttle shaft because of too much fuel in the bowl, once the engine is no longer running. Fuel will not leak at this point when the engine is running, as there is engine vacuum which would prevent leakage. The three most common reasons for leakage around the throttle shaft: (1) FLAPS kit with fuel valve orifice too large, (2) electric fuel pump, (3) modern fuel (it hasn't been gasoline for decades). The professional would NOT use the FLAPS kit, so (1) would not apply on a professionally restored unit, but if (2) or (3) are present, then the restored unit would leak.
Jon
