I've messed with B carbs quite a few times. There is a lot of interection between ignition timing/dwell and idle settings on the carb. I've got mine dialed in pretty well. Initially I couldn't do it. It turned out that the distributor was worn out and the dwell angle walked around all over the place. I swapped it out for a good one and set the dwell and timing, then did the carb. A few minor tweaks on the idle mixture and float setting and it runs great now- no leaks, starts easy after months of sitting, etc.
You never want to mess with both timing and carb stuff simultaneously- if you are doing a tuneup, do the ignition first and drive it a few days before you mess with the carb. Carbs get blamed for bad ignition and bad ignitions get blamed for bad carbs. I never set the point gap with a feeler gauge any more- I use a dwell meter. Its ok to set timing by ear but dwell is a lot tougher to do. Once the distributor gets old the point gap isn't a reliable indicator of dwell angle any more.
As lousy as the "B" is, it can be made to idle really well- as long as it isn't dumping gas down the throat. I had to replace the float on mine to get it to work right, its been reliable for 3 years now.
And for Pete's sake, never change the condenser unless you know its bad. The new ones are such poor quality that you'd better buy 3 or 4 until you get a good one.
