Today I put medium springs in my distributor and set the FBO plate to 10 deg advance. Fired it up and set the initial to 24 degrees. Still has a Top Fueler idle but with 272@.050 I can't say that's a surprise.

Idle vac only about 5" and quite unsteady. I hooked up the can to a Mity-Vac and gave it a squeeze... the timing mark suddenly changed a huge amount and the engine died. Let off the vacuum and it caught again. What I think that's telling me is there's a phasing problem, but not with the rotor to cap (the vac advance moves the pickup plate, not the rotor). Only the centrifugal advance moves the rotor relative to the cap

Just to add to the fun, as the engine was coming to a stop the second time, I let the distributor pickup wires get caught in the alternator belt/pulley and it ripped them up.

But it's not all bad - looking at the mess, I realized that I'd connected the wires backward from the reluctor pickup... which is probably also causing my phasing problem!

Fuel pressure also 4.5 lbs, idle mixtures 1.5 turns out, secondaries cracked... lots of things still to tune. Oh well, enough for one day!