Rochester B is incredibly easy to rebuild. My first rebuild ever. You've assembled an engine. You can rebuild a B.
A kit is cheap and worth a try. But I'm not completely convinced that's your problem.
Several posts back, someone suggested playing with the timing by loosening the clamp and working back and forth while running. Did you ever try that?
Before you even go there, I would make 100% sure that the rotor is pointing at #1 while being 100% certain that cylinder 1 is TDC of compression stroke. And then double or triple check your firing order around the distributor. (Don't ask me why I feel so strongly about this particular check).
