Probably a couple of different issues running in this thread:
Assuming proper float adjustment, fuel leaking from around the throttle shaft is normally caused by fuel expansion once the engine has been shut off. The underhood heat expands the fuel in the fuel lines, creating pressure that the float cannot stop, and dumps fuel into the carb. This raise the fuel level above the main discharge nozzles, and the fuel runs out the discharge nozzle down on to the throttle plate which is closed. It then runs out of the throttle body by the throttle shaft and onto the manifold. THIS ISSUE IS NOT LIMITED TO ROCHESTER CARBS. The issue may be be minimized by installing a "return line" to the tank.
Now as to the Rochesters: Crazyfish, I would certainly agree that the Rochester is an upgrade to the Solex carbs and I would also agree with Chevman32 that they CAN be made to run (although I think Chevman32 could do even better with a different carb). I have been one of those who has said bad things concerning the Rochester B's, but with lots of experience. We used to restore a few here in the shop (never many, because the cost was WAY TOO HIGH for any except those building show cars); and we could make them work, and work well.......for a while. The absolute metering design of the Rochesters is not bad (although I personally think the Carter, Stromberg and Zenith are superior). Crazyfish - the Zenith to which I refer is the USA-built Zenith, not the all pot metal British version you mentioned. The problem of the Rochester B arises in the use of only 4 screws holding the airhorn to the bowl. This leads to warpage. For best results, the warpage MUST be removed. This is done using heat and pressure, never the removal of metal. This process is labor intensive, and thus drives up the cost of the restoration. The problem is that the warpage reoccurs after a few years. And then has to be straightened again!!! I am just lazy enough to believe that a carburetor should deliver at least 100,000 miles of trouble-free operation, assuming the operator changes the air and fuel filters at recommended intervals. The above sentance does not describe the Rochester B.
Oh, and to emphasize that last point, I put a Carter AFB on my six cylinder shop truck of a different brand when I bought the truck used at 140,000 miles. The truck logged another 400,000 WITH NO CARBURETOR SERVICE before the Missouri rust bugs ate the body the third time; and we retired the truck.
Do it right once, and then enjoy it!
Jon.
