I am telling you from experience, on a larger 13B engine with a SP port, it was much faster with 50s in the primary and 61 in the secondaires.

PS: I doubt you was really running lean, it would have popped and backfired really bad., why don' you try turning your timing down some, and see what you get out of it then. That way it doesn't advance as much, unless you disconnected that already, and made the secondaires mechanical, and not vacuum operated?