You can't just swap parts between rochesters willy-nilly- the metering orifaces in the power valves are not all the same. They are also very sensitive to float level, and tend to leak if the float isn't floaty enough. The float design is really marginal and just barely has enough bouyancy to close the needle valve, so if the float hangs up or the brass has a hole in it, it will flood.
The Carter is a much better carb if you have one.
