Thanks for all your help, Dom. You're definitely teaching me more about carbs than I want to

Meanwhile I drilled a pair of 3/32" holes to the secondary throttle plates, about 1/4" in from the transfer slot/idle ports as instructed. Now it idles at 1100 (6" vacuum) or 1200 (smoother, 7" vac) with the transfer slots in the right place, the PCV system connected, AND the timing set at 24 initial! Sounds pretty nasty out back. Wideband dances a bit between 13.5 and 14 when fully warm. It does not want to idle consistently at 1000 or slower.

Opening the throttle to 2000+ (no load) makes 15" of vacuum which will certainly activate my advance can. Should I really limit it to only another 5 degrees?

I still need lighter springs in the distributor because it didn't sound like it was all in until well over 3000 (no helper available today to read the tach). Maybe reset the FBO disc from 10 to 12 deg while I'm in there (for 36 deg all-in if that's safe on pump swill).

Also I'm definitely going to install an oil separator in the PCV line. I agree that burning oil on purpose is generally a bad idea