Very very very FIRST thing is "where is the timing" and I DON'T mean "by the marks" without checking them.
You sure the timing is BEFORE tdc and not after? Try this......hook up your vacuum gauge, gently turn the dist CCW and see if vacuum increases. "Peak" the reading for max vacuum, and back your idle speed down with the screw as the vacuum goes up
THEN check your marks. Don't be surprised if it's 10BTC. Try re-starting the engine several times to be sure it does not kick back on the starter
IF the marks don't make sense, you need to CHECK the marks for accuracy using a piston stop Google "piston stop" or "how to use." Lots of info there
So with timing set for a fair amount of initial advance, AT LEAST 4BTC and perhaps 10, get the engine warm, and adjust the idle MIXTURE screws out some until the enge starts to slow. Keep the idle speed fairly low with the curb idle speed screw. Turn the screws slowly in, watching the vacuum, and listening. At some point, engine will slow a bit, vacuum will drop. THIS IS A subtle indication, you have to "watch" for it. Screw in/ out until you are sure this is right. Go back and forth between the two mixture until the peak is "right on." Then turn each screw in CW a bit for the "lean" side of the peak. idle speed / vacuum should drop the tiniest bit or not at all.
Last, reset your idle speed.