Can't get it to idle right!

Are you running a PCV valve? Give it as much initial timing as it likes. Then check to see how far open the primaries are to keep it running. You may need to increase idle air bypass by either getting a different PCV valve, cracking the secondaries open a little or drilling small holes in the primary throttle plates. Once you get it to settle down a little you need to see if it has enough vacuum to keep the metering rods pulled down at idle. If not you need to get a spring kit. Definitely check for vacuum leaks. If it smooths out when you choke it a little by hand you are losing vacuum somewhere or clogged idle circuits.