Mark - we obviously did have a failure to communicate. I have apologized publicly (in this forum) for my part in this (as you have also).
Unfortunately, with most Rochester carburetors produced prior to the 1968 year; identification when the tag is removed is exceedingly difficult.
What I was trying to convey to you, and didn't, was that Rochester probably made some 1500 or so different type B (we are still assuming you have B's and not monojets). These used 3 different series of main metering jets. These metering series or styles of jets differ in height of orifice and internal approach angle. While the three series can physically be interchanged, the metering will not function as designed, if the incorrect style is used.
You are correct that our minimum is a rebuilding kit. We occasionally take some flack for not selling individual parts without the purchase of a kit. However, this was a business decision which allows us to provide a MUCH larger selection of parts, and still stay in business.
But back to trying to help you acquire the jets. One of the problems with the Rochester B series is commercial rebuilders (true with other carb series as well). The commercial rebuilders interchange parts from many different individual carburetors (often with little regard to whether or not they should be interchanged) and then REMOVE the tag.
Each casting of the Rochester has a casting number. This is a number for an unmachined casting, so this is not an absolute identification; but at least one can get a idea of the time period from the casting numbers. Some time ago, I published some of this information concerning some of the early and mid-50's Rochesters used by Chevrolet on these forums. You might look for this in the archives. If you are unable to find it, I will try to locate my notes and post it again. Most of the early and mid 1950's Chevrolet B's all used the same series of jets. The later one's did not.
One thing you can do until you are able to locate jets is to lower the fuel level in the carburetor bowls. Lowering by a 1/16 inch should give you the same result as installing 1 size (.003) leaner main metering jet. I would still suggest looking at the operation of your power valves.
Good luck with your project.
Jon.
