Large rpm drop

Here's where I'm at:
Pulled the carb, lots of transfer slot exposed. Squared it up, figured out how many turns from 0.020" to 0.040".

Put it back on the car, fiddled around to keep it running. Transfer slot at 0.040" secondaries barely cracked open timing at 30*, idle mixture screws 1 turn out from seated, fuel pressure at 6psi, float level checked, 14-15 inhg on vacuum gauge plugged into full manifold vacuum. ~600 rpm in neutral, ~450 in gear, nothing higher. Black, rich smoke in exhaust, enough to fog surrounding neighbors.