The morning drive showed more improvement in the bog than anything else - the more aggressive pump cam. I didn't get much secondary action but it's all relatively low-speed surface streets around me and I could only boot it once or twice without attracting the wrong attention.
I set the butterflies to the recommended positions before installing the carb - square slot on the primary, just-closed on the secondary. From above, it doesn't look as if they've shifted or changed any.
I'll try the richer initial setting but all indications are that it's running too rich across the board already. Plugs vary from clean-black to slightly sooty.
These are all on *very* short test drives, all I can manage at the moment. A freeway run takes over twenty minutes, time I can't spare much right now. I'm trying to tinker a bit at a time, which is not the most effective or efficient method.
The pump cam (blue, switched from stock pink) has had the most positive effect of all the changes. It's not perfect, but it reduced the bog when cold and seemed to have eliminated it on the homeward (warmed up) leg.
And, FWIW, I finally found the calculation for power valve choice. Most references are as irritatingly vague as everything else: "Go up/down a few sizes on the jets" "try a different pump cam" "go to a different power valve." According to the BG manual, I should be running about a 6 - meaning 5.5 or 6.5. It's got the stock 6.5 in it, so it's not something I'm likely to change out except in final dyno tuning.
Fine, fine, I'll go spin the idles out for my next test drive.